The Cubs, who began the day leading the National League in hitting, have been stymied in the past three games by Philadelphia's Brett Myers and Jamie Moyer, and now Oswalt.
"This guy [Oswalt] is a good pitcher," Piniella said. "The Phillies threw some good pitching at us. These are the type of guys you're going to have to hit. Today, we didn't."
Forgive us for finishing Piniella's thought, but these are the type of pitchers the Cubs will likely have to deal with in the postseason. Oswalt (13-9) gave up four hits over 8 1/3 innings, struck out three and did not walk a batter.
"He's good," Lee said of the Astros right-hander. "He's always good. We probably made him look a little better than he really was -- one hit or two hits or whatever he gave up, we should be able to do better than that -- but Oswalt is always good."
The Cubs have lost three in a row for the first time since mid July when they dropped the last game before the All-Star break, then lost the first two to open the second half, July 18-19, which also were against Houston. The Astros are the only NL Central team with a winning record against the Cubs (7-6).
Despite the loss, Chicago maintained a 4 1/2-game lead in the Central, as Milwaukee lost Monday to the New York Mets.
"We're not happy losing three in a row, but we know we have a good team," said Jason Marquis, who took the loss. "We have a decent cushion, not only in the division, but in the Wild Card race. We don't want to have a letdown. We're still grounded, we're still playing hard. Tomorrow is a new day. We have a good enough team to get to where we want to go. It's a matter of execution, playing hard and minimizing our mistakes."
Marquis (9-8) struck out a season-high eight batters over six innings, giving up two runs on five hits and three walks. It's his highest strikeout total as a Cubs pitcher, and most since he fanned eight Astros on April 22, 2005, while with St. Louis.
Tejada tripled to lead off the Houston fourth, lining the ball off the left-field wall. The ball then caromed into foul territory, and because it hit the dirt and not the grass, it rolled all the way to the Cubs' bullpen mound with Alfonso Soriano in pursuit.
"It reminded me of when I was a little kid, trying to catch a chicken," Soriano said. "We did that in the Dominican."
Lance Berkman then walked, and Tejada scored on Geoff Blum's sacrifice fly. Hunter Pence added an RBI single to go ahead, 2-0. Tejada singled to open the eighth and eventually reached third before scoring on a wild pitch by Jeff Samardzija.
Piniella noted the late-afternoon shadows might have been a factor, but the Cubs players wouldn't use that as an excuse.
"The shadows go for both teams," Marquis said. "It's not like they disappear when they hit or appear when we hit. You have to play the field as it is, and it's equal opportunity for both teams."
Here's a strange stat: The Cubs' past 27 hits have all been singles. The last extra-base hit was Soriano's homer in the eighth inning Friday. Piniella met with his coaches immediately after the game to discuss how to get the team out of this funk.
"We'll see what we do," he said.
What can they do?
"Just keep swinging," Lee said. "It happens. It's just baseball. You go through it. We've gone through it a couple times before. You just keep swinging, and you come out of it."