Jacob deGrom went to the outfield and started playing catch on Monday at Citi Field, and followed it up with a bullpen session — making it three straight days the right-hander has thrown.

The revelation marked deGrom’s first bullpen session amid his injury concerns.

DeGrom was expected to be evaluated by team medical director Dr. David Altchek on Monday, the same day he was initially expected to get an MRI exam on his sore elbow that landed him on the injured list.

The defending NL Cy Young Award winner complained of the soreness after playing catch on Thursday and he went to the IL Friday.

DeGrom said Sunday in St. Louis he “felt completely normal” and Mickey Callaway said later an MRI exam might not even be necessary.