Steven Souza: The 26-year-old Rookie

Steven Souza destroyed Triple-A pitching last season. In 96 games with Triple-A Syracuse, the outfielder hit a gaudy .350/.432/.590, and and kicked in 26 steals for good measure. All told, his offensive exploits generated a wRC+ of 180, which was the highest of any player with even 100 plate appearances in Triple-A last year.

With that showing, Souza made it clear that he was ready for a new challenge. However, as a member of the Washington Nationals organization, he was blocked by incumbent starters Bryce Harper, Jayson Werth and Denard Span. Additionally, he was competing with Michael Taylor — another hotshot outfield prospect who made a mockery of the minor leagues last season.

Souza’s path to the majors became a lot more clear last December when the Nationals dealt him to the Tampa Bay Rays in the deal that sent Wil Myers to the San Diego Padres. As a Ray, Souza’s only real competition is Brandon Guyer, David DeJesus and Mikie Mahtook. Clearly, the Rays are placing a lot of faith in their rookie right fielder.

Souza isn’t your typical rookie. Most prospects who are projected to have significant big league impacts are in their early 20’s. Souza, on the other hand, will celebrate his 26th birthday in April. Believe it or not, Jason Heyward, Giancarlo Stanton, Starlin Castro and Freddie Freeman — who feel like they’ve been around forever — are all younger than Souza. Still, despite his age, Souza’s gotten a fair amount of hype in prospect circles this winter. Baseball America, John Sickels and our very own Kiley McDaniel each placed him in their respective top 100 lists.

Based on his excellent 2014 season in Triple-A, KATOH forsees a respectable 5.2 WAR from Souza through age-28, which puts him 60th overall among current prospects. By itself, this sounds pretty modest. However, considering Souza’s already entering his age-26 season, that forecast is much better than it appears on the surface. KATOH’s essentially projecting Souza to average 1.7 WAR over the next three years.  This jibes his 2015 projections from Steamer and ZiPS, which project him for 1.6 and 1.4 WAR respectively.

Unlike many players who took until age-25 to reach Triple-A, Souza wasn’t some late-round draft choice who consistently played above his tools. He was actually taken in the third round — as a third baseman — back in 2007, but completely stalled out in the low minors. In his first four years as a pro, Souza hit an uninspiring .226/.326/.360 between Rookie Ball and A-Ball.

But something seemed to click for Souza in 2012 — his fifth season in A-Ball. Between Low-A and High-A, the then-23-year-old broke out with a .297/.366/.572 batting line. For the first time as a pro, Souza was hitting for power. But thanks to his five-year bump in the road, he was extremely old for his level.

In 2013, Souza followed up his breakout campaign by crushing it once again in Double-A. Then, last year, he elevated his game to the next level with his other-worldly performance in Triple-A. From 2012 through 2014, Souza went from being a mildly intriguing A-Baller to banging on the door of the majors.

Having an excellent season in Triple-A is great and all, but the jump to the majors isn’t always a seamless one. There have been plenty of hitters who mashed in Triple-A only to hit like utility infielders in the big leagues. To see if Souza might run the risk of facing a similar fate, let’s look at some hitters similar to Souza, and see how they transitioned. Below, you’ll find a list of all hitters since 1990 whose league-adjusted walk rate, strikeout rate, BABIP, ISO and stolen base frequency fell within 1.5 standard deviations of Souza’s marks. I also included their big league stats from the following year.

Year	Name	Age	PA	WAR	WAR/600
2003	Bobby Crosby	23	623	2.6	2.5
1994	Marty Cordova	24	579	3.6	3.7
2007	Ben Francisco	25	499	1.7	2.0
2008	Chris Dickerson	26	299	1.7	3.4
2005	B.J. Upton	20	189	-0.4	-1.3
1991	Derek Bell	22	184	0.7	2.3
1993	Tony Tarasco	22	144	0.2	0.8
1996	Rod Myers	23	121	0.7	3.5
2011	Collin Cowgill	25	116	0.1	0.5
2010	Trent Oeltjen	27	91	0.2	1.3
1994	Dwayne Hosey	27	87	1.6	11.0
1992	Dave Silvestri	24	26	0.4	9.2
2006	Shin-Soo Choo	23	20	0.2	6.0
1999	Chris Latham	26	0	0.0	0.0
1993	Chipper Jones	21	0	0.0	0.0
2014	Steven Souza	25	?	?	?

For the most part, these Triple-A studs adapted pretty well to life in the big leagues. Of the players who received a decent amount of playing time, B.J. Upton’s 2006 season is the only one that I’d characterize as bad. And you could even talk yourself into throwing out that data point. It’s not clear that Upton’s age-21 season tells us all that much about what Souza might do as a 26-year-old.

There’s always the chance that Souza will follow in the footsteps of Colin Cowgill. Like Souza, Cowgill was an outfielder who raked in Triple-A as a 25-year-old, but forgot how to hit upon arriving in the majors. However, the more likely scenario has Souza providing value to the Rays. Marty Cordova, Ben Francisco and Chris Dickerson — all mid-20’s outfielders — are good examples of what Souza might be capable of next year: An better-than-average bat with adequate defense in an outfield corner.

Yes, Souza has been old for his level for years now, but the “old for his league” caveat means less and less the closer a hitter gets to the majors. And when a hitter performs like Souza did in Triple-A, you absolutely have to take notice. More often than not, hitters who rake in Triple-A turn into serviceable big leaguers, regardless of how old they are.

Souza may be older than most rookies, but he’s done nothing but hit in each of the last three years. And if his 2014 performance is any indication, he’s more than ready for the show. At 26, Souza’s closer to his decline years than most rookies, so his peak will likely be shorter than most fellow prospects’. But short peak or not, he has the looks of a useful major league outfielder who’s ready to start contributing right now.