After winning the first three games of a six-game homestand, the Cards dropped two of the next three to the Nats to close out at 4-2. They will now head on the road for four games against the Rockies and three against division rival Houston.
"It's disappointing. This is a big game to miss," La Russa said. "You're trying to get back to .500. Offensively, we just had a tough day."
Both of the Cards' losses in the weekend series came against left-handed pitchers. Friday night, Micah Bowie pitched five innings, giving up two runs. The converted reliever got his first win in nearly five years.
On Sunday, lefty Matt Chico got the start and shut out the Cardinals through four innings. He left after the fourth because of a 61-minute rain delay. Chico came into the game with a 5.54 ERA, but that didn't prevent him from shutting down the Cards offense.
The Cards are now batting .249 against lefties this season. Adam Kennedy, Jim Edmonds and Scott Rolen are all batting below .200 against southpaws, and Chris Duncan is not much better at .214.
"The guys in our lineup should be doing damage against left-handers, and some of these games we just don't produce enough," La Russa said.
"I wish we could figure that out," Scott Spiezio said.
They won't have to wait long for another chance to solve it. The Cards face another lefty, Jeff Francis, on Monday in the series opener against the Rockies.
The sluggish performance by the Cardinals bats overshadowed a dominant performance from starting pitcher Adam Wainwright.
Wainwright had one of his best starts of the year, going seven innings and allowing just two runs on seven hits. He didn't walk a batter and struck out six. The only low spot for Wainwright came in the fifth inning.
With steady rain falling on Busch Stadium, Wainwright hung a curveball to former teammate Ronnie Belliard and was made to pay. With one runner on and two outs already recorded in the inning, Belliard hammered the pitch into the Nats' bullpen for a two-run homer that gave the Nats a 2-0 lead. Home-plate umpire Tom Hallion stopped play one batter later and sent the teams in for a rain delay.
"I didn't really have struggles today," Wainwright said. "You look at two or three at-bats, and that was it. The course of a game is going to be dictated by two or three at-bats sometimes, and today was one of those times. I was pretty locked-in today."
When Wainwright came back from the rain delay, he continued his solid outing. Before being lifted for a pinch-hitter in the seventh, he retired the next seven hitters he faced and didn't allow a ball out of the infield.
"I'm making strides, for sure," Wainwright said. "There are positives to be taken from it, but we didn't win the game. That's what matters."
Unfortunately for Wainwright, the Cards bats didn't do much, though they did mount a legitimate rally in the sixth inning. Still trailing by two runs, Spiezio started the inning off with a single. Albert Pujols followed with a double to put runners on second and third with no outs. Juan Encarnacion delivered a sacrifice fly during the next at-bat to score Spiezio and move Pujols over to third.
Rolen then came up and struck out swinging before Yadier Molina flew out to center field to end the threat. The Cards weren't able to do much outside the sixth.
The Nats added five runs in the eighth off Cards relievers Russ Springer and Randy Flores. Springer gave up a hit and a walk to put the first two runners on. After Flores allowed a run then got two outs, Ryan Langerhans came through with a two-out grand slam to break the game open for the Nats.
"We played good Cardinal baseball for the most part [on the homestand]," Wainwright said. "We had our chances to come in and play good and get things back on the right track, and for the most part, we did."