First, why wouldn't you put him on the 60 day DL? I can't tell how long he's really injured but he's a minor leaguer that you don't intend to call up.
Second, the off-season is 110 or 117 days. Or something like that.
Finally, chest injuries aren't the same as shoulder injuries for pitchers. But his stamina took a hit so that will definitely improve with injury recovery.