Ian Krol is in his first season with the Detroit Tigers, and so far he has been the pitcher the Tigers were looking for.
With Drew Smyly‘s return to the starting rotation this season, the Tigers needed a replacement in the bullpen. Smyly was dominant last season, going 6-0 with a 2.37 ERA out of the pen. He was one of the few consistent members of a bullpen that struggled mightily, but the Tigers saw him as a starter and wanted to move him back to that role.
This past offseason, the Tigers identified Krol as a potential replacement and then traded for him, sending starting pitcher Doug Fister to the Washington Nationals in exchange for Krol, top pitching prospect Robbie Ray and utility infielder Steve Lombardozzi.
Like Smyly, Krol started off his career as a starter, making Baseball Prospectus’ Top 100 Prospect List prior to 2011, but an elbow injury followed by a suspension and then a poor start to the 2012 season saw Krol shift to the bullpen. He made his big league debut in that role last season with the Nationals and pitched well enough to catch the eye of the Tigers.
Since the move, Krol has been one of the Tigers’ best relief pitchers. He currently has the lowest ERA in the bullpen (2.19), is tied for the lowest WHIP on the team (0.97) and has yet to walk a batter this season.
Not allowing any walks has been the key to Krol’s success. He has showed a tendency to give up home runs, allowing five in 27.1 innings last season and three so far in 12.1 innings this season, but keeping runners off base before giving up the home runs this season has led to improved numbers.
Krol has pitched well enough that his numbers stack up well next to Smyly’s from a year ago. Last season, batters hit .219 off Smyly and had a .265 on base percentage. This year, batters are hitting .240 off Krol, but they get on base at a .255 clip. As left-handed relievers, both pitchers tend to be used in situations that match lefty on lefty, and in those situations, the two pitchers numbers are quite similar. Lefties had a .189 batting average and a .225 on base percentage against Smyly last year, and they have a .200 batting average and a .231 on base percentage against Krol this year.
It is still early in the season and Krol’s numbers are taken from a small sample size, but if he can continue pitching the way he has early and limit the long balls given up, he has the chance to post numbers that could arguably be better than Smyly’s last season.