MILWAUKEE -- Manager Phil Garner described his closed-door meeting with general manager Tim Purpura and the coaching staff Wednesday morning a "good, open exchange of ideas."

But clearly, they weren't sitting around talking about how neat it is that Carlos Lee is on the cusp of becoming the all-time home run leader among Panamanian-born players. No, there are bigger issues to deal with. The team entered Wednesday's series finale in Milwaukee with a 32-45 record, good for fifth place in the National League Central.

Purpura finds all of this "unacceptable." And changes are coming. Soon.

"With the way we're going?" Purpura said. "Certainly. This is unacceptable. You can't keep going like this."

Changes may not be made as early as Thursday, when the team returns to Houston for an 11-game homestand, but Purpura isn't ruling that out. And he shouldn't, considering the team is nearing the halfway point of the season and hasn't come close to establishing itself as a contender.

"We're sorting through the possibilies," Purpura said. "I'm not going to stand around and watch us play this poorly. It's not right to the club, it's not right to the fans.

"But what you can do? I don't know. You look in the [Minor League] system, move some guys on, try to make some trades. We'll look at all of that and see what's possible."

The biggest issue currently plaguing the Astros is the bullpen, which allowed 32 earned runs over 20 1/3 innings, for an ERA of 14.19, in the first eight games of the road trip.

Purpura is clearly dismayed by the recent results, but in some ways, he's not all that surprised that the bullpen is struggling.

"I still go back to the loss of [Brad] Lidge being a key component to what's going on here," he said. "Guys are forced into different roles, roles they might not be familiar with. I think that's a big part of it."

Lidge was placed on the disabled list last week, not long after he regained the closer's job he lost to Dan Wheeler early in the season. Lidge's injury forced Wheeler back to the closer's role, while Chad Qualls, Rick White, and, in Garner's words, "et al," were expected to share the setup duties.

Simply put, the disarray has created somewhat of a mess.

"[Lidge is] a guy that we counted on in the seventh and eighth innings for the better part of two months," Purpura said. "He did his job tremendously and he worked himself back in the closer's role. [His absence] hurts us a lot, whether he's the ninth-inning guy or the seventh-or-eighth-inning guy. It's a loss."

Purpura also hinted that Chris Burke will be worked into the mix once Craig Biggio reaches his 3,000th hit, which should arrive in the next few days. Purpura senses Biggio's revamped playing schedule will be a transition, but it's somewhat obvious he's going to play less in the second half of the season.

"We'll play it as he goes," Purpura said. "If he's contributing to the club, he'll play. If he's not, he won't -- at least, not as much. Everyone realizes we need to find out what Chris Burke can do at second base, what our options are in the future. [Biggio will] be in the mix, but I would think it won't be to the same extent.

"It'll be a transition. [Biggio] is a guy, too, that if he's on the bench and you need a pinch-hitter, he's a pretty good pinch-hitter to have."

Speaking of Lidge: Lidge threw aggressively during a long-toss session prior to Wednesday's game and will throw a bullpen session Thursday. The closer is hoping to come off the DL prior to the All-Star break, but he also understands it wouldn't make sense to push himself just to have an appearance or two prior to the four-day layoff in mid-July.

"If I'm feeling pretty good but not great, it probably doesn't make sense," he said. "But if I'm feeling really good, then it might not be a bad thing to get in a game or two before then, be able to rest for four days and come back full strength. We'll have to wait and see."

Coming up: The Astros will return home Thursday to begin an 11-game homestand that will take them into the All-Star break. Right-hander Roy Oswalt (7-5, 3.55) will take the mound for the Astros in the series opener with the Rockies, who will counter with right-hander Aaron Cook (4-5, 4.93).