HOUSTON - Jarred Cosart, the Astros' top pitching prospect who was promoted to Triple-A Oklahoma City on Friday, joined his new team in Omaha on Saturday and was brimming with excitement. He went 1-2 with a 2.84 ERA in four starts at Double-A Corpus Christi.

"They told me to come up here and stay awhile and go from there," Cosart said. "I have to keep doing what I've been doing. It's really close now [to reaching the Majors], but it's a great feeling to have. Hopefully in a few weeks or months I'll get another call."

Cosart, one of four players the Astros acquired from the Phillies in last year's Hunter Pence trade, said he will start Monday for the RedHawks against Omaha. Right-hander Aneury Rodriguez was originally scheduled to start that game, but the Astros announced Saturday night he was coming up to start Tuesday against the Marlins.

Rodriguez, who went 1-6 with a 5.27 ERA in 43 games (eight starts) for the Astros last year, is 1-3 with a 4.97 ERA at Oklahoma City.

"From what we understand he's progressed and thrown the ball real well, and I'm kind of anxious to see him," Astros manager Brad Mills said.

Weiland discusses shoulder surgery

HOUSTON -- Wearing a sling and sporting an IV port he uses to receive his antibiotics treatment, right-hander Kyle Weiland met with reporters Saturday for the first time since undergoing surgery on Tuesday to clear up an infection in his right shoulder.

Weiland, acquired in December in a trade with the Red Sox, said the shoulder "locked up" on him about a week before he was diagnosed.

"They jumped on it right away and went in there to flush it out and get as much of the infection out as they could, and they have me on a heavy dose of antibiotics," he said. "As of right now, everything is going according to plan. We'll keep monitoring it and make sure it's not coming back so I can get back as soon as we can."

Weiland, who went 0-2 with a 6.62 ERA in three starts this year, will be out indefinitely. He hopes to pitch at some point this season, but it's clear Weiland will be sidelined for at least the next few weeks, if not longer. When he's healthy enough to pitch, he'll need a lengthy Minor-League rehab to build up arm strength.

"As soon as I can start moving the arm and the stitches are out, I'll start getting my range of motion back and build up the arm strength," he said. "From there, it's just a matter of time. It's just like starting from square one. Hopefully within the next couple of months, we'll be throwing."

Cruz scheduled to throw in Triple-A rehab stint

HOUSTON -- Relief pitcher Rhiner Cruz, who's been on the disabled list since April 24 with a right ankle sprain, was scheduled to throw one inning on Saturday night in a rehab stint for Triple-A Oklahoma City at Omaha. He's also scheduled to throw Monday before being re-evaluated.

Cruz, a Rule 5 Draft pick who throws as hard as 100 mph, appeared in seven games for the Astros and was 1-0 with a 2.08 ERA, with eight strikeouts and four walks in 8 2/3 innings.

"We got to the point we were relying on him quite often," Astros manager Brad Mills said. "We're going to see how he throws tonight and how he throws Monday and see where he is. He might be pretty close. We don't know."

Mills hasn't been shy about using Cruz in tight situations because of his ability to get a key strikeout. While Brett Myers' spot is secure in the bullpen as the closer, Mills said he's typically been using his relievers based on matchups.

"You look at the types of hitters they're going to face and see if there's an advantage," Mills said.

Worth noting

• With Bobby Meacham away from the team for two days to attend his son's college graduation in Colorado, Astros special assistant to the general manager/player development Dan Radison coached first base on Saturday and will do it again Sunday.

• Center fielder Jordan Schafer, who has tied the club record by reaching base safely in 25 consecutive games to start the season, was out of the lineup Saturday against the Cardinals. Astros manager Brad Mills said Schafer badly wanted to play, but Mills wanted to get Justin Maxwell, who started in center field, some at-bats.