Phil Hughes and the Sobering History of Thoracic Outlet Injuries

The Twins designated Phil Hughes for assignment on Monday, bringing to an apparent end the 31-year-old righty’s five-year run with the team and perhaps marking the end of his 12-year big league career. On a superficial level, his is a tale of a big-money contract gone wrong, as the Minnesota media — which knows red meat when it sees it, as fan perception of Joe Mauer’s long decline phase attests — was quick to take note of the team’s $22.6 million remaining salary commitment. On a deeper level, Hughes’ tenure with the team is a reminder of the fragility of pitchers’ bodies in general, and the ravages of thoracic outlet syndrome, for which Hughes underwent surgery not once but twice. The annals of such surgeries feature few happy endings.

Hughes had thrown just 12 innings this year, allowing four home runs while being pummeled for a 6.75 ERA and a 7.62 FIP. After starting the year on the disabled list due to an oblique strain, he returned on April 22 and failed to escape the fourth inning in either of his two starts. Sent to the bullpen, he made five appearances, the last three each separated by one day of rest. While his average fastball velocity (90.4 mph according to Pitch Info) was back up to where it was in 2015, his last reasonably healthy season, it sounds as though manager Paul Molitor felt hamstrung when it came to finding situations in which to use him.

“I guess it was somewhat comparable to almost a Rule 5 situation where you’re trying to find the right spots, and they were few and far between,” Molitor told reporters on Monday night.

The Twins have a week to trade or release Hughes, assuming he isn’t claimed on waivers, which is unlikely given the money he’s owed for the remainder of this year and next. The team did not ask Hughes to accept a minor-league assignment, nor did they try to stash him on the disabled list so that he could spend more time on a rehab assignment.

Sadly, injuries have always been an essential part of the Phil Hughes Experience. The Yankees’ 2004 first-round pick out of a Santa Ana, California high school dealt with shoulder inflammation, elbow tendinitis, and a herniated disc in his first two professional seasons. He made his major-league debut on April 26, 2007, and in his second start threw 6.1 no-hit innings before suffering a pulled hamstring and a subsequent high ankle sprain that together sidelined him for three months. After being battered for a 9.00 ERA in six starts in 2008, he was diagnosed with a stress fracture of a rib and made just two more appearances in late September. Having finally established himself as an above-average starter in 2010, he missed nearly half of 2011 with shoulder inflammation (at which point, he was also tested for TOS, but the tests came back negative). He was hampered by a bulging disc in 2013, sidelined by lower back inflammation in 2015, his best season, and suffered a fractured femur via a line drive to his left knee in 2016.

In between those multiple maladies were certainly some highlights. After he struggled in the rotation in early 2009, the Yankees moved Hughes to the bullpen, where he posted a 1.40 ERA and a 1.83 FIP in 51.1 innings while serving as a setup man in front of Mariano Rivera; he helped the team win the World Series that fall. Returning to the rotation in 2010, he posted a 1.39 ERA and a 2.49 FIP over his first six starts, a performance that helped him earn a spot on the AL All-Star team despite doing rather mediocre work (5.02 ERA, 4.80 FIP) over the remainder of the season; he finished with a 4.19 ERA, a 4.25 FIP, and 2.6 WAR. He rebounded from his injury-wracked 2011 season with a healthy 32-start, 2.4-WAR campaign in 2012.

Hughes did a bellyflop in his final year before free agency, posting a 5.19 ERA and a 4.50 FIP while allowing 1.5 homers per nine; his 14 starts of fewer than five innings is still tied for the highest total since division play began in 1969. Nonetheless, the Twins reasoned that spacious Target Field might prove a more hospitable environment for the young fly-baller than Yankee Stadium and the other AL East crucibles, and they signed him to a three-year, $24-million deal. Hughes initially rewarded their faith with a career year worth 5.9 WAR. He posted a 3.52 ERA and a 2.65 FIP in a career-high 209.2 innings, along with 8.0 strikeouts per nine, a league-low 0.7 homers per nine, and a record-setting 11.6 strikeout-to-walk ratio — personal bests across the board.

At the end of that stellar season, the Twins were so taken by Hughes’ polite refusal of a chance to pitch in relief and record one out so as to earn another $500,000 in bonuses that they tore up the final two years of his original deal and signed him to a new five-year, $58 million extension. He regressed almost immediately, allowing seven homers in his first four starts en route to an AL-high 29, served up in just 155.1 innings; his season was worth just 1.1 WAR. He was dreadful in 2016 (5.95 ERA, 5.08 FIP in 59 innings) before the fractured femur.

While on the disabled list, the shoulder fatigue he was experiencing was finally diagnosed as TOS, which is caused by a compression of the nerves and/or blood vessels somewhere between the neck and the armpit. Symptoms commonly include numbness or tingling in the fingers and hands, or fatigue or weakness that doesn’t go away with physical therapy and rest — issues that don’t go well with the pitching lifestyle. Pitchers tend to be particularly vulnerable to TOS because of their repetitive overhand movements and the way their arm muscles build up. The condition is generally remedied by the removal of a cervical rib and two small scalene muscles.

Hughes was similarly dreadful in 53.2 innings last year while battling biceps tendinitis and then suffering a recurrence of TOS symptoms. He underwent revision surgery for the removal of the remaining piece of the rib that had been partially removed the year before. So far as I can tell, he’s the first major-league pitcher to undergo TOS revision. The Rangers’ Matt Harrison had two TOS surgeries, but the first was on his left (throwing) shoulder in July 2009, and the second on his right shoulder in September 2013.

Though his eight-year major-league career was marked by numerous injuries including spinal fusion surgery in 2014, Harrison actually counts as one of the success stories in the annals of TOS. Building on the research that Craig Edwards did in connection with Matt Harvey’s 2016 TOS diagnosis, I updated his table of 17 major-league pitchers who have undergone the surgery since 2001, adding additional performance data. As readers have pointed out, Bill Singer in 1966 and J.R. Richard in 1980 are two examples of earlier pitchers who underwent the surgery (Singer had a long, successful career thereafter, while Richard never returned).

The count is now up to 27 pitchers, with Carter Capps, Luke Hochevar, Tyson Ross, Nathan Karns and Vince Velasquez having followed in Harvey’s wake. (Edwards also seems to have missed counting Clayton Richard, and we both missed Nate Adcock, Daniel Bard, Mike Foltynewicz and Nick Tepesch, until readers alerted me.)

Here’s the table, ordered by post-surgery innings (for Hughes and Harrison, the numbers are with respect to their first TOS surgery):

Pitchers Who Underwent Thoracic Outlet Syndrome Surgery
Pitcher Yr surgery Age IP Pre ERA- FIP- IP Post ERA- FIP- ERA- dif FIP- dif
Kenny Rogers 2001 36 2049.1 92 95 1253.1 94 101 2 6
Aaron Cook 2004 25 256.1 105 102 1150.0 92 99 -13 -3
Matt Harrison 2009 24 147.0 125 114 521.1 87 98 -38 -16
Alex Cobb* 2011 23 52.2 88 91 446.0 92 94 4 3
Clayton Richard* 2014 30 773.1 114 113 368.1 110 99 -4 -14
Kip Wells 2006 28 983.2 100 104 354.2 132 116 32 12
Chris Young 2013 34 890.2 92 101 348.1 107 135 15 34
Mike Foltynewicz* 2015 23 105.1 146 133 330.1 102 101 -44 -32
Jeremy Bonderman 2008 25 994.2 107 93 236.1 139 127 32 34
Jaime Garcia* 2014 28 594.2 92 89 230.2 100 100 8 11
Matt Harvey* 2016 27 519.2 79 72 133.2 157 141 78 69
Josh Beckett 2013 33 1935.1 91 89 115.2 83 119 -8 30
Tyson Ross* 2016 29 670.2 98 89 102.2 127 112 29 23
Phil Hughes* 2016 30 1204.2 106 98 65.2 135 132 29 34
Vince Velasquez* 2017 26 258.2 107 100 47.1 112 99 5 -1
Drew VerHagen* 2016 25 50.1 103 111 44.1 133 125 30 14
Mike Adams 2012 34 363.2 56 71 43.2 95 111 39 40
Shaun Marcum 2013 31 995.0 94 100 35.0 132 143 38 43
Nate Adcock 2014 26 95.0 91 109 28.0 138 153 47 44
Nick Tepesch* 2015 25 219.0 111 118 19.2 150 192 39 74
Chris Carpenter 2012 37 2207.1 86 88 17.0 96 106 10 18
John Rheinecker 2008 28 121.0 120 108 0.0 N/A N/A N/A N/A
Noah Lowry 2009 28 618.1 92 102 0.0 N/A N/A N/A N/A
Daniel Bard 2014 29 257.1 85 97 0.0 N/A N/A N/A N/A
Luke Hochevar* 2016 32 929.1 117 104 0.0 N/A N/A N/A N/A
Carter Capps* 2017 26 147.2 110 82 0.0 N/A N/A N/A N/A
Nathan Karns 2017 29 310.2 109 108 0.0 N/A N/A N/A N/A
Pitchers ranked by post-surgery innings totals. Negative ERA-/FIP- differentials indicate improvement with respect to park-adjusted league average

The average total of post-surgery innings for the group is just 218, compared to an average of 657 innings prior. Excluding the three recent pitchers who have yet to return to the majors and the three who never did (Lowry, Rheinecker and Bard), those figures rise to 732 pre-surgery and 281 post-surgery. The relatively heavy post-surgical workloads of Cook and Rogers skew those figures; even excluding the zero-innings guys, the medians are just 595 innings pre-surgery and 134 post-surgery. As many as 13 of the pitchers on the list might still be considered active, though VerHagen is in the minors and Hochevar unsigned, so all of the aforementioned figures could rise with the passage of time.

Given those relatively modest post-surgical innings totals and the performance data, the numbers are rather sobering, and that’s while keeping in mind that pre-surgical performance may have suffered due to the symptoms that led to the diagnoses. Of the 21 pitchers who returned to action, only five lowered their ERAs relative to the league across any sample (Beckett, Cook, Foltynewicz, Harrison, and Richard), and only five did so with respect to FIP (Cook, Foltynewicz, Harrison, Richard, and Velasquez). The ERAs of four other players rose by less than 10% (Garcia, Velasquez, Cobb, and Rogers), with Cobb and Rogers the only two about whom the same can be said with respect to FIP; these pitchers were still quite serviceable if not exactly as effective after the surgery as before, and from that group, all but Rogers are still active, which is to say that they may yet join the first group.

At the other end of the spectrum, 10 of the 21 returnees saw their ERA- rise by more than 20%, and 10 did so with respect to FIP-, including Hughes (an ERA- 29 points higher, a FIP- 34 points higher). Harvey had the largest gains of the group, which is to say the largest fall-off in effectiveness (an ERA- 78 points higher, a FIP- 69 points higher), though at least he’s been trending in the right direction since being traded to the Reds. Ross, who struggled mightily last year, his first since surgery, has been much more effective this year (90 ERA-, 88 FIP-) and might be the strongest candidate to escape this sad group, at least in the near future.

That leaves very few pitchers in the middle ground — namely, the recently retired Young with respect to ERA-, VerHagen and Wells with respect to FIP-, and Carpenter with respect to both, albeit with just three post-surgical regular-season outings before retirement.

As Edwards noted, there’s no clear pattern here. The strongest correlations I found were between age and post-surgery ERA- (r= -.27) and pre-surgery innings and post-surgery ERA- (r = .21), both of which suggest, unsurprisingly, that younger or more lightly-used pitchers have tended to fare better with recoveries. Many of these pitchers have dealt with other major injuries and surgeries that could have had a further impact on their effectiveness. Adcock, Capps, Carpenter, Cobb, Garcia, Harvey, Hochevar, Marcum, Velasquez, and VerHagen all had Tommy John surgery prior to TOS surgery, and both Carpenter and Garcia are among those who had endured labrum surgeries as well.

All of which is to say that Hughes is hardly the first pitcher to see his performance decline to the general vicinity of replacement level in the wake of TOS surgery. His contract extension with the Twins may not have worked out, to the chagrin of the Twins and their fans. The real story, however, both for Hughes and for so many other pitchers here, is that his body betrayed him, and that’s hardly his fault. Here’s hoping he can find his way back.

Brooklyn-based Jay Jaffe is a senior writer for FanGraphs, the author of The Cooperstown Casebook (Thomas Dunne Books, 2017) and the creator of the JAWS (Jaffe WAR Score) metric for Hall of Fame analysis. He founded the Futility Infielder website (2001), was a columnist for Baseball Prospectus (2005-2012) and a contributing writer for Sports Illustrated (2012-2018). He has been a recurring guest on MLB Network and a member of the BBWAA since 2011, and a Hall of Fame voter since 2021. Follow him on Twitter @jay_jaffe... and BlueSky

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Alex Chamberlainmember
5 years ago

FYI – Nate Karns pending return from TOS.