When the Detroit Tigers acquired Yoenis Cespedes for Rick Porcello at the MLB Winter Meetings last December, pitchers Alex Wilson and Gabe Speier were viewed by many as "throw-ins" in a one-for-one deal. The Tigers viewed the trade differently, however, as Cespedes is not eligible to receive a qualifying offer after the season. Porcello would have been eligible, but he signed a four year, $82.5 million contract extension with Boston on April 7.
Early returns on this trade have been very promising, particularly due to Wilson's performance in the bullpen. After beginning the year with 5 1/3 scoreless innings at Triple-A Toledo, Wilson has held opponents to a 1.99 ERA and 0.71 WHIP in 22 2/3 innings at the major league level. He has been somewhat of a long relief specialist for the Tigers, and threw three scoreless frames in the first start of his MLB career on Wednesday, a 3-2 Detroit victory.
Before the season, I hypothesized why Wilson went from an also-ran in 2013 to one of the better relievers for the Boston Red Sox in 2014. Wilson missed part of the 2013 season with a ligament injury in his right thumb, then underwent offseason surgery to correct the issue. When he returned to action in 2014, Wilson was a changed pitcher. He held opponents to a 1.91 ERA and 0.88 WHIP in 28 1/3 innings for Boston last year.
The result was a big change in his pitching repertoire. After relying almost entirely on his fastball and slider in 2013, Wilson was able to throw his cutter 32 percent of the time in 28 1/3 innings in 2014. Opposing batters hit .132 with a .237 slugging average against the cutter. An unsustainable .213 overall BABIP was mostly due to a scant .118 BABIP against the cutter. Opponents hit the cutter for a line drive just 17 percent of the time, barely above the 14 percent pop-up rate it generated. It didn't garner a lot of whiffs (cutters aren't really supposed to), but it induced a lot of bad contact.
There were other improvements too. Wilson's walk rate dropped, he dominated righties, and he induced a lot of weak contact on pitches outside of the strike zone. A 28-inning sample is too small to draw many conclusions from, but there were a lot of signs that the Tigers were getting someone better than Wilson's nondescript pedigree suggested.
This season has been more of the same for Wilson. He is throwing his cutter 30 percent of the time, holding opponents to a .172 batting average. He has lowered his walk rate from 4.6 percent last season to just 3.8 percent this year, which has improved his strikeout-to-walk ratio to 5.33. Even his BABIP has stayed low, sitting at .203 through 22 2/3 innings.
Wilson's cutter hasn't been quite as dominant in 2015, but he has gotten better in other aspects. He has improved his swinging strike rate from 6.8 percent last season to 8.1 percent in 2015, and he is inducing more swings outside the strike zone than ever before. He has even shored up his issues against left-handed batters, holding them to a .186 average with 13 strikeouts to two walks in 45 plate appearances.
The biggest underlying difference in Wilson's performance in 2015 has been his fastball command. The cutter has remained devastating to both righties and lefties, but Wilson uses his fastball more often against left-handed batters. In 2014, he was prone to leaving the ball up, resulting in a .297 batting average and .649 slugging average to all hitters.
This season, Wilson is both keeping the ball down and hitting the outside corner. He has not allowed an extra base hit on a fastball yet this year, and opponents are hitting just .167.
Wilson is also throwing more first pitch strikes, which allows him to use his four-pitch arsenal more unpredictably. Opponents are hitting a paltry .162/.205/.216 off Wilson when he gets strike one this season, and .203/.221/.365 for his career.
It's hard to say that Wilson will continue pitching at this level despite having done so for his last 51 innings. A .203 BABIP is awful low, and Wilson doesn't have the power stuff that many dominant relievers do. The Tigers may benefit from giving him some more high leverage innings in the future, as the team is just 4-9 in games that he pitches in. However, there is also value in eating low leverage innings efficiently, and Wilson has passed that test with flying colors so far this season.