SAN DIEGO -- Rangers manager Ron Washington hasn't named a starter for Friday night's series opener with the Rockies, but Roy Oswalt bolstered his candidacy with a strong start in Triple-A Round Rock on Sunday.

The Rangers signed Oswalt after Neftali Feliz's elbow injury in late May. Since then, the veteran righty has made four Minor League starts, and Sunday's was the best. After pitching to a 7.50 ERA in his first three outings, Oswalt threw 100 pitches and 70 strikes over six innings, yielding just two runs and one walk in Round Rock's 4-2 victory.

"I feel like I'm ready. The plan was six starts, but after tonight, I feel pretty well," Oswalt said after Sunday's game. "Everything's coming out of my hand pretty well. The ball's kind of jumping on guys. That's what I was looking for."

Oswalt said he hopes his next stop is Arlington, where the Rangers return Friday after a three-game trip to San Diego.

"He was good ... had a good breaking ball," Washington said. "I think that was one thing that was missing in his other starts. You know he's got a changeup, know he can spot the fastball, so we have a decision to make, but we haven't made it yet."

As the Rangers' rotation stands, Justin Grimm, who earned a win against the Astros in his Major League debut Saturday, would be Friday's starter. Washington said he and his staff have not made a decision on Oswalt or Grimm, though he was adamant that skipping the struggling Scott Feldman -- scheduled to pitch Tuesday night -- is not an option, even with an off-day Thursday to allow the rest of the rotation to catch up on rest.

"I do believe if we decide something on Oswalt, it could change what we have," Washington said. "But we're not going to prematurely do something because we haven't discussed it yet."

Hamilton gets into opener, eyes Tuesday start

SAN DIEGO -- Rangers outfielder Josh Hamilton was not in the starting lineup for Monday night's series opener with the Padres, though he entered late in the game.

Hamilton, who has been out of the lineup since leaving last Thursday's game with a stomach virus, plans to be in the lineup for Tuesday night's game.

Hamilton decided early in the day to take some extra time to ensure he would have the stamina to make it through a full game.

"My stomach's a little jacked up, but I hit early BP and it feels good," Hamilton said. "Told 'Wash' [manager Ron Washington] when I got here today I didn't wanna jump back into anything as far as the game. I wanted to come back in, get some work in, see how my body responds to it."

Apparently it responded well, as Washington used Hamilton in the ninth inning of the Rangers' 2-1 victory in left field.

Hamilton, who is hitting .330 with 22 homers and a Major League-leading 62 RBIs, lost 10 pounds, and the virus forced him to be hospitalized Friday, though he had recovered enough by Sunday to return to the Rangers.

Washington said before Monday's game that he would have started his star in the series opener had Hamilton told him he was ready.

"He just wanted to work and see how he felt," Washington said. "He didn't want to go out there and then third or fourth inning say he can't make it. ... The way he was running balls down in the outfield and the way he was swinging the bat, it looked like he's gonna be fine."

Washington said there are no concerns about Hamilton spreading the virus to other players, though Hamilton's family was also afflicted. His wife and daughter also battled the virus, though he says all are now home from the hospital and almost over the illness.

"I don't know where we got it, but we got it, and it's over ... mostly," Hamilton said. "It's June. You don't wanna rush back out there, set yourself back, and then be out even longer. If everything goes good I'll jump back in there tomorrow."

Injured pitchers Feliz, Holland get in throwing

SAN DIEGO -- Rangers right-hander Neftali Feliz threw Monday for the first time since being placed on the disabled list May 21 with a sprained elbow. He was moved to the 60-day DL and is eligible to return July 18.

According to manager Ron Washington, Feliz threw lightly from about 40 feet before Monday's game, just to "get his arm going." The righty was 3-1 with a 3.16 ERA in eight games (seven starts) prior to the injury and has not pitched since May 18.

Starter Derek Holland also threw before Monday's game. The left-hander has been on the DL since June 7, when weakness resulting from a stomach virus forced the 25-year-old out of action. Holland's workout included tosses at 100 feet on flat ground.

"The next step will probably be letting him stand on the rubber," Washington said. "He's getting back. It was his weight loss, it wasn't that he was injured. He's been looking good."

Rangers prospect Perez delivers strong start

ROUND ROCK -- Martin Perez, winless in his last six starts, delivered his best performance of the year Friday.

Heading into his most recent start, Perez, 21, was 0-3 with a 7.48 ERA in his last six outings with Triple-A Round Rock, which lost each of those games. But the southpaw rebounded Friday against Oklahoma City, the Astros' Triple-A affiliate, tossing seven scoreless innings in a 2-0 victory. Perez allowed only one hit, struck out five and walked five while throwing 61 of his 101 pitches for strikes.

"I think the problem I've had in the last month is my mind. I was thinking too my much," said Perez, ranked second among the Rangers' top prospects. "Before the last start, I changed my routine before the game. I threw more in the bullpen and long-tossed for about 10 minutes. I threw my fastball in. When I have good command in, I can go to both sides with my off-speed pitches. That's what I'm going to try to do from now on."

Perez was one of a few pitchers that the Rangers likely considered to fill the spots in their rotation left vacant by injuries to Derek Holland and Alexi Ogando. Justin Grimm eventually got called up from Double-A Frisco and earned a win in his Major League debut in Saturday's 8-3 win over the Astros.

Perez proved Friday why he's regarded as one of baseball's top Minor League players. He lowered his ERA from 5.40 to 4.90 and has posted a 4-5 record this year, striking out 45 and walking 36 in 14 starts.

-- Christian Corona

Worth noting

• Ryan Bores, the Rangers' 27th-round selection in this year's First-Year Player Draft, hurled six innings of two-run ball in Kent State's 5-4 elimination-game win over top-seeded Florida on Monday in the College World Series.