PHILADELPHIA -- The Astros were forced to take pregame batting practice inside for the fourth consecutive game Tuesday after inclement weather kept the tarp on the infield. The tarp was on the field for batting practice in the final two games of the Marlins' series and in Monday's series opener in Philadelphia.

Manager Brad Mills would like his young infielders to take as many ground balls as possible on the field, especially considering many of his players hadn't played at Citizens Bank Park before this series.

"I'm really disappointed we're not on the field today for batting practice and ground balls," Mills said. "There are a few things we're going to work on defensively. We wanted to get Carlos [Lee] some ground balls out there since he's playing first, but we can't do that."

Mills was also hoping to get a better look at veteran infielder Geoff Blum, who has been bothered by a sore neck. Blum is available to pinch-hit, but Mills wanted to see how he fared fielding grounders in batting practice before making a decision on whether he's ready to play defense.

Quintero's arm keeps players on toes

PHILADELPHIA -- The strong arm of Astros catcher Humberto Quintero -- and his penchant to show it off by throwing unexpectedly to the bases -- paid dividends Monday night, when Quintero picked off a surprised Jayson Werth at second base to end the sixth inning.

Pitcher Brett Myers, who, as it turns out, helped Quintero's cause by distracting Werth by sticking out his tongue at his former teammate, had just completed an intentional walk to Carlos Ruiz when Quintero fired a laser to second baseman Angel Sanchez, who tagged out Werth while he was scurrying back to the base.

"You never know with Q," Myers said. "He's always firing the ball around because he's so accurate. He can throw the ball and put it on the spot every time. It's good to have a catcher back there that works with you well and is able to throw the ball he way he can. It shuts down the running game, and I'm comfortable with him back there. He saw something and he's smart enough to make that play and fire it down to second."

Quintero leads all catchers with five pickoffs, despite starting only 59 games, which is a career high for him.

"Yes, he has a strong arm, but his release is so quick," manager Brad Mills said. "You see guys take two or three steps to throw that ball or have a big arm motion. He makes his mind up to throw the ball, and the ball is on the way and is accurate and hard, and that's what is so good about his snap throws."

Said Werth: "The whole time, I was thinking, 'After he threw the first pitch, if he doesn't pay attention here, I could probably steal third.' I'm still thinking like that before that [fourth] pitch, then he looks at me and ... I was smiling as the ball was on its way. So between that and the little smokescreen where I got shielded on -- and that was the main reason -- it was terrible."

Lindstrom to get on mound Wednesday

PHILADELPHIA -- Astros reliever Matt Lindstrom, who's been on the disabled list since Aug. 16 with a lower back strain, is scheduled get on the mound Wednesday when he throws in the bullpen before the game. Lindstrom threw off flat ground twice last weekend in Florida and is feeling better.

"Getting out there and playing catch, it was the first time in a little while, and I kind of felt like myself," Lindstrom said. "I'm looking forward to getting back out there and helping my teammates. It's tough sitting here and watching the guys play good. I look forward to jumping back in there and landing on my feet when I get off the DL."

Lindstrom, who is eligible to return from the disabled list Aug. 31, was dealing with back issues for several weeks before he was finally put on the DL following a series of bad outings. That cost him a chance to pitch against his former team, the Marlins, last weekend in Miami.

"You don't plan on things like this happening," Lindstrom said. "I probably should have tried to get it fixed a little bit earlier, but I've been stubborn. There are certain things you can battle through and certain things you can't, and this is one of those things."

Back issues not slowing down Byrdak

PHILADELPHIA -- Astros left-hander Tim Byrdak had not allowed a run in 28 of his last 29 outings entering Tuesday, which is even more impressive when you consider Byrdak has been battling through some abdominal and back issues.

Byrdak, who was on the disabled list in May with a strained hamstring that was related to an irritated disk in his back, is still feeling some discomfort. He believes a sports hernia could be causing his back to stiffen, and was hoping to get examined while in Philadelphia by Dr. William Meyers, the same doctor who examined teammate Brian Moehler's groin injury last week.

But Meyers was out of town this week.

"It's nothing I can't handle, but it's a nagging deal," Byrdak said. "If it's tight [near his lower abdomen], it's pulling at other places. If I could get that to relax, maybe everything else would relax and maybe it takes the focus off that more. I've never had anything like this."

Byrdak, who had cortisone shots in May and then again in early June to help his back, hopes to get an MRI at some point to help diagnose the problem. He said he might have even explore having surgery in the offseason to fix the problem.

"It's responded pretty well, but it's a nagging thing," he said. "You want to wake up and feel pretty good. You just want to wake up and not feel anything and be good to go. We're still going to get to that point and making adjustments here and there and doing what I can do."

Worth noting

Astros right-hander Brian Moehler, who has been on the disabled list since July 8 with a right groin injury, was forced to leave his rehab start Tuesday for Triple-A Round Rock against Oklahoma City with discomfort in his groin. He went three innings, allowing one hit and one run.