Game 72 Preview: Red Sox at Tigers

Boston Red Sox (44-31) at Detroit Tigers (40-31)

Time/Place: 7:08 p.m., Comerica Park

SB Nation blog: Over the Monster

Media: Fox Sports Detroit, MLB.TV, Tigers Radio Network

Pitching Matchup: LHP Jon Lester (6-4, 4.37 ERA) vs. RHP Doug Fister (6-4, 3.21 ERA)

Last time Jon Lester pitched at Comerica Park, he was really good. He held the Tigers to one run in seven innings on Opening Day of the 2012 season and ended up with a no decision after both closers imploded. Since then, things haven't gone so well for him. He struggled with a couple of nagging injuries in 2012, ending the season 9-14 with a 4.82 ERA/4.11 FIP/3.82 xFIP. He got off to a much better start this season, winning six of his first nine starts with a 2.72 ERA. In his last six starts, he is 0-4 with a 7.20 ERA.

One of the issues that has plagued Lester over the past couple seasons is a drop in fastball velocity. From 2009 through 2011, Lester's fastball averaged 94.4 miles per hour and he struck out 9.4 batters per nine innings. Over the last two seasons, his average velocity has dropped to 93.5 miles per hour and his strikeout rate has decreased to 7.4 batters per nine innings. While we can't be certain that the drop in velocity is causing his drop in strikeout rate -- the whiff rate on his fastball hasn't changed over the years -- the two are likely correlated.

Lester's struggles as of late are largely due to a lack of command. He has walked 18 batters in his last 35 innings after walking just 15 in his previous 59 2/3 frames. The same fastball we mentioned above has failed him during this rough stretch. He has allowed seven homers in his last six starts, all of which have come off fastballs.

Doug Fister must have felt that the heavens opened up in his last start, because the five runs of support he received against the Twins were more than in his previous four starts combined. That didn't stop Fister from putting together a brilliant outing, taking a no-hitter into the sixth inning before allowing a couple of runs over his last two-plus innings of work.

Overall, Fister has gotten into a great rhythm early in each of his last five starts. He has worked very efficiently, pitching at least seven innings in each outing. He has also struck out 33 batters in 38 innings while only issuing five walks and plunking two more batters. His curveball and cutter have been his better pitches in terms of whiff rate, but his two-seam fastball is what is getting the job done. Opposing hitters are pounding it into the ground 60% of the time they put it in play, resulting in an ISO of just .075 this year.

Outlook

A big component of Boston's success this season is what their left-handed hitters have been able to do offensively. Red Sox lefties are hitting .292/.369/.502 against right-handed pitchers this season, which is by far the best OPS in this situation in the American League. They also lead the AL in stolen bases, though Jacoby Ellsbury is responsible for more than half of the team's total. However, Fister has excelled in both of these departments as well. He is holding lefties to hitting just .200/.261/.244 this season, and has only allowed two stolen bases in five attempts. It will be interesting to see who wins this matchup tonight, especially if Lester can keep the Tigers offense in the doldrums early on.

Prediction

Fister keeps rolling and Joaquin Benoit picks up his first save as the "official" closer.