​Boston Red Sox pitcher Aroldis ChapmanAroldis Chapman has not pitched since Sunday, and when he was not used with a one-run lead in the ninth inning on Thursday, interim manager Chad Tracy was asked for an explanation.Tracy said that Chapman was dealing with lat tightness. With the regular season winding down, that is not something that any Boston Red Sox fan wants to hear.“We’re going to be conservative with (it),” Tracy said postgame, per MLB.com’s Perla Paredes. “It’s getting better, but we’re going to make sure it gets there. That’s why he wasn’t available tonight.”The good news is that Tracy said it’s getting better. The Red Sox have Garrett Whitlock, who is more than capable of closing games, and some more bullpen reinforcements potentially on the way. However, Chapman has been one of the most dominant closers in baseball throughout his career, especially in Boston.Looking for the perfect gift for a baseball player in your life? Check out our brand-new baseball lifestyle brand!Chapman was the American League Reliever of the Year last year, posting a 1.17 ERA in 67 games. This year, he has a 1.95 ERA in 52 games and has 34 saves. The Red Sox’s duo of him and Whitlock figures to be very important in October, but the 38-year-old needs to be healthy for that.“Obviously, you guys know how diligent he is about his prep and getting in and getting treatment. So we’ll just monitor it day to day,” Tracy said.More MLB: Johan Oviedo Wants To Return In Any Role To Help Red Sox After Missing Nearly Entire Season