ANAHEIM -- Brad Lidge is going to miss significant time in the near future after suffering a strained oblique muscle in his left side. He was placed on the disabled list following Tuesday's game, and the Astros filled the closer's roster spot by purchasing the contract of lefty Stephen Randolph from Triple-A Round Rock.

Dan Wheeler will resume the closer's role he lost to Lidge on June 8, when the team was in Chicago to play the White Sox and Cubs.

Lidge suffered the injury during his last outing last Friday in a relief appearance against the Seattle Mariners. He could be activated from the DL on June 30, but it's more likely that he'll be out for longer than the 15 required days.

"He needs to shut it down," manager Phil Garner said. "It'll be awhile where he won't do any throwing activity. If he keeps trying to go, it'll get worse and worse. I've never seen it get better when a guy keeps trying to play with it."

Lidge headed to the outfield for batting practice Tuesday hoping he would be able to play catch without pain, but that experiment failed.

"I was hoping when I went out and threw that I wouldn't be feeling it and it wouldn't be bothering me, or it would be mild enough to where I could throw through it," he said. "That just wasn't the case. I just want to try to get it better as fast as possible before it keeps me out for a real long period of time."

The only true remedy for an oblique strain is rest, which is why it often takes longer to recover from this injury.

"The unfortuanate part is I can't do a whole lot," Lidge said. "I'll lose a little arm strength, so I'll have to be real patient. I'm not someone who likes sitting around all day and that's kind of what I'm going to have to do here. Hopefully, we can get it better as fast as possible and I won't have to miss any more than 15 days."

Discipline? Prior to batting practice Tuesday, Chad Qualls had not heard from team officials regarding any disciplinary actions that may be taken after his ball-throwing incident during Monday's game. That doesn't mean he's not going to receive punishment, however.

"I have no idea," Qualls said. "I hope not. I haven't gotten any phone calls about it."

As of game time Tuesday, general manager Tim Purpura hadn't heard from league officials, either.

Qualls blew a five-run lead in the seventh inning Monday, which allowed the Angels to tie the game at 9. When he walked off the field, he forcefully threw the ball to the top deck of Angel Stadium in a burst of anger.

Qualls was in no mood to discuss the throw at length following the game, but after sleeping on it, the right-hander was able to take some jabs at himself for the rare outburst.

"I just say the fans in the first couple rows always get balls, and the guys in the third deck never get a ball," he joked. "Now they did. From what I was told from some people, it supposedly went out of the stadium."

Qualls' outburst wasn't an isolated incident. Cameras have caught Astros players in various stages of distress recently, ranging from Dan Wheeler's shove of Chris Sampson during a recent loss to Oakland, to Lance Berkman's toss of a trainer's bag onto the field in Colorado a couple of weeks ago.

"We're making highlights for all the wrong reasons," Qualls said. "It's out of sheer frustration."

As for who gets the award for the best on-field outburst, it appears to be a "toss" up.

"It would have been better if it went completely out of the stadium," Qualls said of his lob to the upper deck. "The ball was definitely lighter than the bag [Berkman threw], but at the same time, everybody throws stuff on the field. Maybe if he would have thrown the training bag out of the stadium."

Aches and pains: Luke Scott appears to have a recurring injury around the left groin area, but the nagging pain wasn't enough to keep him out of Tuesday's lineup.

"I tweaked it a little bit [Monday] night," Scott said. "It's just one of those nagging injuries that I've got to kind of take care of. I'm trying not to blow out of the box so hard -- that's probably the most important."

Scott was lifted from Tuesday's game for a pinch-runner in the fifth after he knocked a double to center. Garner said he pulled him for precautionary reasons.

"I noticed him wobbling a little bit in the field earlier," Garner said. "When I saw him come out of the box and run toward second, I didn't feel he was running good enough. If we had to score, it might be hard for him to score."

Odds and ends: Chris Burke is tentatively slated to play second base on Wednesday, while Craig Biggio will be the designated hitter. ... Roy Oswalt, who will start Saturday's game in Arlington against the Rangers, has 105 career wins, good for sixth place on Houston's all-time win list. He's one away from tying Nolan Ryan for fifth all-time. ... The Astros have four Interleague games remaining on their '07 schedule, one with the Angels and three with the Rangers.

Coming up: The Astros and Angels will conclude their three-game Interleague series on Wednesday night at Angel Stadium, beginning at 9:05 p.m. CT. Left-hander Wandy Rodriguez (4-6, 4.19 ERA) will face right-hander Ervin Santana (5-7, 5.04).