The team reportedly knows about the situation but expects Arrieta will be able to wait until the offseason to have surgery.

Arrieta pitched Saturday night in a 6-5 loss to the New York Mets, giving up six runs (five earned) on 11 hits in 4 1/3 innings. He took the loss, sending his record to 8-7 with a 4.67 ERA.

"Physically, I'm not in a great spot," Arrieta said afterward, per ESPN. "I think we'll have a better idea over the next couple of days where I'm at."

Arrieta also hit three batters during the game and was frustrated in the locker room, hinting that there was a physical issue, according to The Athletic.

One of the players he hit, Todd Frazier, was ejected for jawing at Arrieta and arguing with the officiating crew.

"Frazier's not happy about it, he can come see me," an equally frustrated Arrieta told reporters. "I'll put a dent in his skull."

The 33-year-old Arrieta had surgery for a bone spur in his arm late in the 2011 season and was ready in time for the start of the following season.