Since sweeping the Cardinals to get within one game of the lead in the National League Central on July 22, the Astros have lost 19 of 31 games and 11 games in the standings. Houston fell, 1-0, in the series opener against St. Louis on Tuesday and lost, 3-2, on Wednesday.
Oswalt, who took the loss on Wednesday, was critical of his team's play.
"The team atmosphere is dead," Oswalt said Wednesday. "There's no fire. When you get on a streak, you come to the field expecting to win. When you're dead, you come to the field just hoping to get by. That's what it feels like around the clubhouse -- just a dead feeling. We've got so far behind it seems like we're going through the motions as a team. You've got to play it out. You've got to play all the games."
Astros manager Cecil Cooper, who wasn't aware of what Oswalt had said until he was asked to comment on it by a reporter Thursday, said he disagrees with his ace.
"I don't think that's the case," Cooper said. "I totally disagree with that. I think this has been two of our better ballgames right here. We just haven't hit. One hit to the left or to the right and it's different ballgames. We win them."
Berkman understands Oswalt's frustration.
"I think he's just concerned about making sure that guys keep playing hard, that we still have a month and a week left," he said. "It's just a situation where it looks pretty bleak in terms of our playoff chances, and in order to guard against complacency, sometimes you have to check yourself and say, 'All right, so what? Let's just keep playing hard and get after it.'
"This has been a tough season for us in a lot of ways. Since we were one game out a month ago, things have gone south in a hurry. We just haven't played as well as we would have liked, and I think there's a lot of disappointment and frustration, and you just want to make sure things are as they should be as we head into the final month of the season."
Berkman doesn't necessarily believe the Astros aren't playing with fire, but said teams in funks sometimes look like they're not playing hard.
"If you don't win, it always feels that way," he said. When you're winning and you're in contention, you talk to any player in the history of the game and they always say, 'This year went by quick because we were in contention,' or if you're out of contention, 'Man, it drags by.' I think where you're at in the standings and how you're playing has a lot to do with the atmosphere of the club."
Hunter Pence, the third-year right fielder, said the message from the veterans carries a lot of weight.
"You always listen to leaders and veteran guys like Lance and Oswalt," he said. "We need to have some fire and play as hard as we can. I didn't say we didn't have it; we just need to have it."