Hunter joined Vladimir Guerrero on the list of injured Angels -- Guerrero left Tuesday night's 8-5 loss to the Rangers with a strained muscle behind his left knee.
Both are waiting for results of MRIs.
Hunter said the pain was so intense that he couldn't run at all on Tuesday night when he went 1 for 5. His groin has been bothering him since May 24 when he crashed into the wall making a catch against the Dodgers.
"As of now, it's a little sore," Hunter said before Wednesday's game. "I've been playing on it for a month. It's just been going downhill."
Hunter is hitting .305 with 17 homers and 65 RBIs.
Guerrero, who had been serving as the designated hitter most of the season because of a pectoral muscle injury, is hitting .290 with four home runs and 21 RBIs. He returned to play right field on Sunday.
"With Torii and Vlad just starting to hit their stride it's really unfortunate," Angels manager Mike Scioscia said.