What It Means:

Red Sox manager John Farrell observed the session and was accompanied by two coaches, two trainers and two physical therapists. Without reading into it too much, the workout concluded with a round of fist-bumps, which implies things went well. Kimbrel will have another session on Wednesday throwing off the mound and pending any setbacks, he could then be given the OK to face live hitters. This puts him on track to rejoin Boston's bullpen by early next week. Brad Ziegler -- and his 2.44 ERA this season -- is the current closer for the Red Sox.

Kimbrel owns a 3.55 ERA and a 3.38 xFIP, which would both be career worsts, in 33 innings pitched this season. Our models project him to record a 3.19 ERA and a 29.30 strikeout percentage (league average is 21.00 percent) over the rest of the season.