What’s Wrong with Francisco Liriano?

After five terrible starts to open the season, it’s time to wonder what the heck is wrong with Francisco Liriano. Finally healthy in 2010, Liriano delivered the best season of his career – in which he finished first in the American League in xFIP and second in the AL in FIP (behind Cliff Lee). This season, Liriano looks less like the Minnesota Twins’ ace, and more like their 25th man. With Kevin Slowey preparing to take over in the rotation, can Liriano turn it around before he loses his spot?

At look at Liriano’s peripherals doesn’t inspire much confidence. Liriano has been absolutely terrible this season, posting an identical strikeout and walk rate of 6.85. The former would rate at a career low for Liriano, while the latter is the worst among all starting pitchers this season. All told, Liriano’s poor performance has led to a 9.13 ERA over his five starts.

While we shouldn’t expect Liriano to continue to be that bad as the season progresses, we also shouldn’t expect much improvement based on his current stats. Despite the struggles, Liriano’s .307 BABIP rates right around his career average. Liriano has also been able to maintain his solid ground ball rate from last season. Even though those numbers have remained consistent, Liriano has still managed to post a 6.05 FIP and a 5.26 xFIP to start the season.

A look at Liriano’s plate discipline charts may reveal the reasons for Liriano’s struggles. Opposing batters have been more reluctant to offer at Liriano’s pitches this season; particularly outside of the strike zone. When batters are swinging at those pitches, they are making contact with more frequency as well. On top of that, Liriano’s slider currently carries a negative pitch type value; the first time in his career that the pitch has been ineffective.

The slider has been a problem for Liriano this season. Hitters aren’t swinging at the pitch as often this season; particularly when it ends up out of the zone. When Liriano throws the slider for a ball, batters are only swinging 27.4% of the time; down from 40.4% last season. That could partially explain Liriano’s poor first strike percentage this season as well. When batters do swing at the pitch, they are making more contact than usual (52.9% this season compared to 37.4% last season). All told, Liriano’s best pitch has completely betrayed him this season. If he hopes to rebound, Liriano is going to have to “find” his slider again.

Due to those struggles, Liriano currently carries the worst swinging strike rate of his career. Liriano’s current 10.6% swinging strike rate is nearly identical to his 2008 rate; the season that ended prematurely after Liriano underwent Tommy John surgery. *As reader dan pointed out in the comments, Liriano was recovering from TJ surgery in 2008. That’s not to imply Liriano is/or will be injured, but it’s another example of his struggles this season.

Unfortunately for Liriano, he doesn’t have a whole lot of time to figure things out. With Kevin Slowey breathing down his neck, Liriano likely only has 1-2 starts before Ron Gardenhire makes a change. Based on Liriano’s current performance, that may not be the worst decision for the Twins. Liriano ultimately has the most talent of any pitcher in the Twins’ rotation, and he proved that last season, but a healthy Kevin Slowey is definitely an upgrade over this version of Liriano.