HOUSTON -- Beginning Wednesday, the role of Astros closer will be played by any one of four pitchers: Dan Wheeler, Chad Qualls, Trever Miller and, occasionally, Brad Lidge.

Manager Phil Garner informed Lidge following the Astros' 18-inning loss to the Cubs on Tuesday night that he was taking him out of the exclusive closer's role and will instead use a bullpen-by-committee format.

Lidge, who gave up a game-tying homer to Matt Murton in the ninth that sent the game into extra innings, was forthright while expressing his disappointment prior to Wednesday's finale with the Cubs. But he also emphasized that he fully understands why Garner made his decision.

"I understand the urgency of our situation now," Lidge said. "We're not in a position to fool around by any means. We need to win games. I understand.

"I'm hoping that I can get back consistently and get back in a spot where I feel I can be in the closer's role. Right now, I understand the urgency for wins and I understand what he wants to do right now. Hopefully, pitching this way will give me an opportunity to get on a consistent roll and we can go from there."

Lidge has five blown saves this season, and over his last 20 appearances, he has surrendered 15 runs on 18 hits with nine walks. He had converted five save opportunities before Tuesday's blown save, his first since July 8.

Garner took Lidge out of the closer's role earlier this year, but it appears this demotion will last longer, likely the rest of the season.

Garner called Lidge's struggles a "mystery."

"When I took him out of the role a little bit [earlier in the year] and told him I may come and get him in the ninth inning, I didn't think he was throwing the ball really well," Garner said. "I think recently, he's been throwing the ball pretty good. He's worked on his mechanics, he seems to have a finish to the plate, his slider's had some good bite. So it is a mystery."

Lidge's only goal is to succeed, regardless of what innings he's called upon.

"For me, the biggest thing is I need to work as hard as I can to make sure our team wins," he said. "To get in there and keep the lead or whatever situation I'm going in, tie game, behind... I need to keep the score where it's at. Obviously, it is disappointing that I'm not going to be closing for right now, but hopefully I can do well and get back in that position."

Teammates react: The Astros bullpen's motto is "one heartbeat" -- "We're brothers with different mothers," Russ Springer likes to say -- so the fact that Lidge's closest friends will be sharing his former closer role will understandably be a bit strange.

"It's a little different, espcially being here in Houston, where I came up in '04, he was the closer," Qualls said. "He was always the guy. Whatever Garner wants is fine. Every win from here on out is important. I'm sure we're all capable of getting the job done. It'll be a little different not having Lidge out there in the ninth some games, but we have to get through that and win some ballgames down the stretch."

The overwhelming sentiment from the relief corps was one of belief in Lidge, whom they feel will be an effective closer again down the road.

"Brad stuggles, we struggle," Wheeler said. "That's just the way it is. None of us wanted this. For us, we're not where we want to be. I know Brad's not where he wants to be. But I know it's in there. I believe it. We just need to get some luck going his way and I think he'll be fine."

It's likely Wheeler is going to get the majority of the save opportunities, but he doesn't plan to change his approach or the way he prepares.

"Whether it's the seventh, eighth or ninth inning, it doesn't matter to me," Wheeler said. "Whatever I can do to help the team win, obviously, I'll just prepare myself. Lately, when I've been down there [in the bullpen], whenever the phone rings, if it's me, it's me. Whether it's the eighth or ninth, it doesn't matter."

Feeling better: Roy Oswalt will test his right wrist for the first time since his injury when he throws on flat ground Thursday in Milwaukee.

Oswalt is still hopeful that he'll be OK to make his start Saturday against the Brewers.

"I feel good," he said. "I have more motion. I'll probably be able to tell by tomorrow."

Umpire's discretion: Normally, when an umpire issues warnings to both benches after a batter has been hit with a pitch, the next pitcher to hit a batter is ejected from the game, as is his manager.

But these ejections are not automatic. The umpire has the ultimate say, which is why Ryan Dempster was not tossed after he hit Chris Burke in the 16th inning of Tuesday's marathon.

Ejecting Dempster would have been ridiculous, considering home plate umpire Jerry Meals issued his original warning 10 innings earlier, in the sixth, when Roger Clemens hit Ryan Theriot. Dempster, the Cubs' eighth pitcher of the game, clearly was not thinking about retaliation three hours after the initial confrontation.

"Even if a warning has been issued, the umpire must deem that a subsequent pitch (which may hit a batter) was intentional," Major League Baseball's vice president of umpiring Mike Port said via e-mail. "If such is judged to be the case, then the pitcher and manager are ejected. In this overall matter, intent [in the judgment of the umpire] is the key."

Defensively speaking: Willy Taveras received a season's worth of trips up Tal's Hill in center field on Tuesday, and judging from his quick reaction time, it's clear he's made significant strides defensively.

Taveras was forced to scamper up the hill three times during the 18-inning game. One ball was out of his reach -- Jacque Jones' 445-foot homer that cleared the very deepest wall at Minute Maid Park. But Taveras also made two effortless catches on balls that sailed toward the wall.

"The play right up against the wall is not an easy play," Garner said. "He made it look easy. It's very difficult."

One of the biggest challenges is switching strides right in the middle of a sprint. Taveras has longer strides when he's running toward the hill, but once he's on it, he has to change to shorter, choppier steps.

"If you can play long enough out there, you know you've got the hill," said Taveras, who works regularly with first base coach Jose Cruz on the hill. "You look at the hill, and you have to be quick. You see it, then you have to make the adjustments while you're running. It's different."

Coming up: The Astros begin another three-city road trip, beginning with a four-game set in Milwaukee. Right-hander Jason Hirsh (0-1, 9.00 ERA) will face Brewers righty Ben Sheets (3-4, 4.98 ERA) in Thursday's opener.