ARLINGTON, Texas -- Veteran starter Roy Oswalt said he plans on throwing Thursday to see how his strained forearm feels.

Oswalt said he's never had an arm injury in his career. When asked if he thought the injury had anything to do with going back and forth between a role in the bullpen and one as a starter, Oswalt replied, "I don't know."

"They wanted me to take three days off and then we'll play catch and see how it feels," said Oswalt, who added he hasn't done anything the past few days to let his arm rest. "I'm going to try to see how it feels tomorrow and then see. I did some treatment and got on some anti-inflammatories."

Oswalt said he felt it the third pitch of his last outing and that it cramped up and just got tight as things progressed. He said his changeup felt the best in that two-inning outing Sunday in Tampa and he threw it a lot.

Oswalt said he's trying to figure out how best to go about figuring out a routine for the bullpen. He's been a starter his entire career and isn't used to not knowing when he's going to pitch.

Other notes:

* Mike Napoli is expected to catch nine innings in tonight's Game 2 of the Texas League Championship Series for Double-A Frisco. The plan remains that he would then be the designated hitter Friday when the series returns to Frisco for Game 3.

* Texas extended its agreement with Triple-A Round Rock through the 2018 season. There had been two more seasons remaining on the original deal.