On Saturday, Pujols had four hits, falling a triple shy of the cycle, in St. Louis' 8-5 loss to the Astros (70-66). He jumped past Atlanta's Chipper Jones for the major league lead with a .362 batting average.

The Cardinals (74-62) have the best record road record in the NL at 37-31, but they've lost their last three road games.

A defeat Sunday would saddle St. Louis with its longest road losing streak since an 11-game skid from Aug. 29-Sept. 25, 2007. That slide also includes the last time the Cardinals were swept in a road series - at Cincinnati from Sept. 11-13.

Pujols, who hit a two-run homer Saturday, is hitting .532 (25-for-47) with eight doubles, five homers, 14 RBIs and 10 runs scored in the last 12 games. The Cardinals, though, are just 6-6 during that span.

He's hit .396 (19-for-48) with six homers in 14 games against Houston this season.

Saturday's loss dropped St. Louis into a tie with the Philadelphia Phillies for second place in the NL wild card standings, 5 1/2 games behind the Milwaukee Brewers. The Brewers are 19-7 in August.

"It means that (Sunday) is a really important game," manager Tony La Russa told the Cardinals' official Web site. "We need to salvage a game in this series, and tomorrow is our last chance. ... You don't want to come down here and get swept."

St. Louis hasn't suffered a series sweep in Houston since a four-game set in September 2006.

After a walk-off loss in the series opener Friday, the Cardinals took an early lead Saturday on Rick Ankiel's three-run homer in the first inning, but Houston responded with six runs off Braden Looper in the bottom of the inning. Ty Wigginton and Hunter Pence each homered and Geoff Blum added a run-scoring double.

Blum also hit a two-run homer in the fifth, again off Looper, to make it 8-3.

"Basically, the guys put three runs on the board for me and if I did my job we would have had a good chance to win the game," Looper said. "Unfortunately, I didn't."

The Astros have won four straight and are 23-10 since July 27. They are 9 1/2 games behind the Brewers.

Todd Wellemeyer (11-5, 3.87 ERA) returns to the mound Sunday for St. Louis after having his three-game winning streak snapped Tuesday in a 12-0 loss to Milwaukee. Wellemeyer allowed five runs - four earned - and eight hits through six innings.

Wellemeyer is 1-0 with a 4.35 ERA in two starts and six relief appearances against the Astros. He did not get a decision in his only game against them this season, allowing two runs in seven innings of a 5-3 loss on April 7.

Wandy Rodriguez (7-6, 3.94) pitched 7 1-3 scoreless innings in that game, allowing three hits while striking out six, but also did not factor in the decision.

Rodriguez will go up against Wellemeyer again as he tries to beat the Cardinals for the first time in four tries this season - he's 0-2 against them despite a 1.45 ERA. Rodriguez is 1-6 with a 4.56 ERA in eight career starts and one relief appearance versus St. Louis.

The left-hander avoided suffering a third straight loss on Tuesday with a strong outing against Cincinnati, allowing one run and three hits with a career-high 10 strikeouts over seven innings of a 2-1 defeat.