Lucas Giolito underwent an MRI on his left hamstring earlier this week, and Thursday morning the Red Sox pitcher provided an update on what the imaging showed.

But on Tuesday, he suffered yet another setback.In his spring training debut against the Philadelphia Phillies, Giolito left after one inning after feeling tightness in his hamstring--tightness that the righty said he experienced on the very first pitch of the outing.

Giolito, who missed last season because of elbow surgery, spent much of the start of camp going through his rehab progression.

With injuries already impacting the Boston Red Sox pitching staff, how much pressure are the starters and new acquisitions under to produce at a high level?

This is particularly true with respect to pitchers, whose injury risk is highest between February and May. We saw this last year with Lucas Giolito, who missed his entire first season with the Red Sox after injuring his arm in Spring Training.