ARLINGTON – Scott Feldman will make his first major league start Sunday, thanks in part to Mother Nature.

Rain forced Thursday's doubleheader, which created an open spot in the rotation. So Feldman gets a chance to see how far he's come after making the transition from reliever to starter in the off-season.

Feldman altered his arm slot, making it closer to a three-quarter, overhand delivery. It has helped create more movement on his pitches to left-handed hitters.

"In a perfect world, we'd like to give him some more time down [in the minors] before we went to him," general manager Jon Daniels said. "But with the way the timing is, we felt he was the best option."

Feldman gave up one run on three hits with a walk and two strikeouts in his lone start for Double-A Frisco last weekend. He has pitched 89 2/3 innings in the majors – all in relief – and is 1-5 with a 4.42 ERA.

By pitching Sunday, Feldman gives Jason Jennings (coming off flexor tendon surgery last year) another day to rest his arm.

Roster moves: The Rangers must make two roster moves this weekend.

When Luis Mendoza is activated to make his start today, it's likely one of the club's sore relievers will go on the disabled list.

Eddie Guardado has a sore shoulder, Jamey Wright tweaked his left oblique muscle in his outing Thursday, and Dustin Nippert's left shin still smarts from the line drive he took off of it in Anaheim last week.

Nippert, who pitched 2 2/3 scoreless innings on Friday, appears the likely choice to go on the DL. To make room for Feldman, the Rangers could send a reliever with options – probably Josh Rupe – to the minors.

Wilson staying efficient: Closer C.J. Wilson said he felt fine after notching saves in both games Thursday.

He threw a total of 18 pitches, but he said he was efficient because he got some of his outs on first pitches. He also notes that he's avoided walks, which extended his pitch counts last season. He also doesn't have a strikeout yet.

"He looks like he's under control more, and he's much calmer," manager Ron Washington said. "He's not wasting pitches, that's for sure."

Briefly: Umpire Mike Winters was behind the plate Friday. Winters was the umpire Milton Bradley was arguing with last season when he was tackled by his manager and injured his knee. There was no incident between Bradley and Winters on Friday.