Alex Wilson's rebuilt breaking ball is his key to big season

When we last saw Alex Wilson, he was fighting a desperate (and ultimately futile) rearguard action as one of the few bright spots in the Tigers' 2015 bullpen. Acquired in the deal that brought Yoenis Cespedes to Detroit from the Boston Red Sox, Wilson didn't even break camp with the Tigers. Yet, after a late-April call-up, his consistency in a wide variety of situations throughout a difficult 2015 campaign was impressive for a guy in his second season in the major leagues.

Yet it wasn't enough to earn Wilson a role protecting leads in the late innings in 2016. Tigers' GM Al Avila, rebuilt the back end of his bullpen this offseason, and with the additions of Justin Wilson, Mark Lowe and Francisco Rodriguez, Alex Wilson is once again back down the pecking order as the fourth or fifth option.

This is great news for Tigers' fans. The depth of the bullpen has already appeared a strength this season. Wilson's return against the Astros on Sunday serves notice that the Tigers' relief corps wasn't even at full strength just yet.

Wilson got off to a nice start on Sunday, as he spun a pair of scoreless innings in his season debut, striking out a pair of Astros' hitters. If he can be as effective in 2016 as he was last season, the bullpen will be all the stronger for his skill and versatility. But there is reason to hope that Wilson may have even more to offer the Tigers in 2016.

There was a time when Wilson posted quite healthy strikeout totals. His three full seasons at Triple-A Pawtucket from 2011-2013 were characterized by high strikeout rates and terrible command. His plus slider was a big reason for those strikeouts. In late 2012, Baseball America even rated Wilson's slider as the best in the Red Sox' system. But in 2013, Wilson suffered a torn ligament in his right thumb that cost him much of the season, and eventually required surgery.

Wilson's command took an enormous step forward in 2014, at least once he was called up by the Red Sox, but his strikeout rates plummeted in the process. While those low walk rates kept his strikeout-to-walk ratio solid, he's allowing a lot of of contact. That's the kind of thing that can eventually burn a pitcher, and it's likely the main reason no one in the Tigers' organization is quite comfortable yet having him protect leads late in games.

As a result of the ligament surgery, Wilson  was forced to shelve his slider in 2014 in favor of a cutter, which didn't generate a lot of whiffs, but did have hitters beating the ball into the dirt regularly. There is evidence to suggest that he either returned to the slider in 2015, or rebuilt the cutter into a very slider-like breaking ball in 2015, one that helped boost his whiff rates over his 2014 campaign.

Spin data tells us that what the chart above refers to as Wilson's cutter is indistinguishable from a slider. This isn't a cut fastball. It's a breaking ball. He may not throw it with a traditional slider grip, and he may refer to it as a cutter, but it  has the spin rate and angle of a normal slider. He's thrown in at 87 mph both seasons, but with very different amounts of spin and movement on it. Perhaps Wilson returned to his slider last year, or he simply started throwing his cutter with movement exactly like a slider. Whatever the name, this is his breaking ball, and it's the pitch that needs to generate more swings and misses if Wilson is going to punch out more hitters.

After producing a 7.5 percent whiff rate in 2014, Wilson got hitters to miss on his cutter 11.7 percent of the time in 2015.  He threw the pitch with less spin in 2015, allowing the ball to drop almost an inch and a half more than the higher spin offering he had in 2014. It also had less horizontal movement, becoming more of a straight breaking ball with more depth. If the pitch continues to generate more swings and misses, Wilson may find the strikeout touch he once had. Even just modest improvement would make Wilson a borderline elite reliever. He'll never strike out a batter per inning, but he could be dominant beyond any vagaries of BABIP with an increase in that department to pair with his typically elite walk rate.

For two seasons, Alex Wilson has proven himself a tough competitor and a pitcher who forces opposing hitters to earn anything they get against him. With no growth at all, the Tigers should still feel pretty good that a guy this effective is the fourth or fifth option out of the bullpen. That's depth the Tigers haven't had in their relief corps at any time during the recent run of four straight A.L. Central titles. Should Wilson's rebuilt breaking ball recapture the strikeout ability he rode to the majors, the Tigers will have a truly dominant reliever on their hands who is comfortable working in any situation.