Delcarmen came into the contest with one out in the eighth, relieving Javier Lopez after just one-third of an inning. Delcarmen promptly struck out Alex Rodriguez looking, but he began shaking his hand noticeably as he walked around the mound.
The Red Sox's staff immediately came to the hill to check on Delcarmen, and he was promptly pulled in favor of lefty Hideki Okajima, who finished off the inning by striking out Jason Giambi.
"The doctor checked it out and there was just a little cramp," Delcarmen said. "It just felt like it kept cramping up on me, like after every pitch, so they just wanted me to get out and see if everything is all right."
Delcarmen said he's felt such a discomfort before, but it has never lingered pitch after pitch. He said it began hindering his command as he could not throw inside quite as easily.
Still, the righty said the doctor massaged the forearm and said it felt good after the game. Manager Terry Francona was relieved, even though taking him out was a no-brainer.
"When you make a trip out there and any pitchers says they feel something in their flexor, that doesn't seem any reason to leave him out there," Francona said. "By the time he got back to the clubhouse and upstairs, it had calmed down. His strength was fine.
"I think there's a chance he might be a little stiff [Saturday]. I don't think there's anything more than that. That was probably me being overprotective, which I won't apologize for."
Delcarmen is 0-2 this season with a 4.46 ERA. He has 13 holds, with his most impressive stint of the season coming throughout the month of June. Between May 27-June 27, a span of 12 appearances, Delcarmen did not allow one run while striking out 16.
Delcarmen said he'll evaluate how stiff it feels on Saturday morning, get some treatment and go from there.
"You really can't control a cramp," Delcarmen said. "But they're going to check it out tomorrow, and hopefully, I'll feel good to go."
Mark Remme is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.