ARLINGTON -- Vicente Padilla has been trying to pitch through some inflammation in a muscle joint on the right side of his neck. It's been a problem since the All-Star break, and the Rangers have twice pushed his next start back a couple of days.

The Rangers have done it again. If he can't make this one though, he could end up on the disabled list.

Padilla has been scratched from Sunday's start against the Rays and pushed back to Tuesday against the Tigers. Dustin Nippert, who has been the Rangers' long man, will start on Sunday against the Rays. The Rangers also optioned Tommy Hunter to Triple-A Oklahoma and recalled Kameron Loe to give them a long reliever in the bullpen.

Padilla, who is 12-6 with a 4.85 ERA in 23 starts, was supposed to throw in the bullpen Friday but couldn't. He'll try again on Sunday. If that goes well, he'll start on Tuesday. If not, he could end up on the disabled list and the Rangers will recall Hunter.

"It's feeling much better," Padilla said before Saturday's game with the Rays. "Tomorrow I'll throw in the bullpen and then decide how I feel. With the time off I've had, it should be good."

Padilla hasn't pitched since last Saturday in Baltimore, when he allowed six runs in four innings in a 9-0 loss. He had a cortisone shot Monday and has been undergoing treatment since then. Nippert will be the 14th different starter used by the Rangers this year.

"It doesn't get any better for us; it just keeps getting tougher," Rangers manager Ron Washington said. "But if he can't go, then he can't go. We just have to keep making adjustments."

Padilla had to go on the disabled list right before the All-Star break because of the problem. He returned with seven scoreless innings in a 1-0 victory over the Twins in his first start after the break. But the problem has grown progressively worse in his last three starts, against the Mariners on July 30, the Yankees on Aug. 4 and then the Orioles.

"When I faced Seattle, I felt it just a little bit," Padilla said. "When I faced the Yankees it was getting worse. Then against the Orioles, I couldn't throw hard. It was really bothering me.

"I started to feel it right before the All-Star Game. I thought [the break] would be enough time for me to come back OK. This season is the first time I've ever had my neck bother me like this, but thank God my arm is OK. It's just my neck."