VIERA, Fla. -- Right-hander Stephen Strasburg had one bad inning and it proved costly, as the Nationals lost to the Cardinals, 6-2, at Space Coast Stadium on Saturday afternoon.

The game was a tuneup for Strasburg, who will be Washington's Opening Day starter against Chicago on Thursday at Wrigley Field. Strasburg pitched four innings and allowed three runs -- two earned -- on five hits. He threw 67 pitches, 43 for strikes.

The three runs against Strasburg came in the second inning. With runners on first and second and one out, Daniel Descalso doubled near the left-field line, scoring Tony Cruz and Erik Komatsu. Descalso advanced to third on an error by shortstop Danny Espinosa and scored on a groundout by Cardinals starter Jake Westbrook.

The Cardinals would add three runs in the sixth inning, this time off left-hander John Lannan. Descalso highlighted the scoring with another two-run double and ended up with four RBIs on the day.

The first Nationals run scored in the bottom of the sixth inning, when Chad Tracy hit a home run over the right-field wall off Westbrook, who went 5 2/3 innings and allowed the one run. Washington added a run in the bottom of the ninth on Corey Brown's RBI single.

"[Westbrook had] just all his normal stuff, throwing strikes, throwing to the bottom of the strike zone, letting his sinker do its thing, same old stuff," Cardinals manager Mike Matheny said.

Westbrook is ready for the season to begin.

"I'm probably about as confident as I've ever been going into the season," Westbrook said. "When the games start counting, you've got to amp up your focus."

Up next: The Nationals travel to Jupiter on Sunday to play the Cardinals for the final time this spring. Left-hander Gio Gonzalez will make his sixth Grapefruit League start and third against St. Louis. In the two games against the Cards, he allowed eight runs in 7 2/3 innings. First pitch is at 1:05 p.m. ET.