Marquis, who won eight games in 2002, has won four straight decisions and six of his last seven after a 1-3 start to the season.
In his last game, a 10-3 win over the Kansas City Royals on Sunday, the right-hander labored through five innings, allowing three runs on seven hits, with one walk and four strikeouts, but escaped with his seventh win of the season.
Marquis, who spent the first four years with the Braves before an offseason trade brought him to St. Louis, can match his career high in wins with a victory on Saturday.
The Cardinals ended a three-game slide with an 11-2 win in the series opener on Friday.
Starter Woody Williams came back strong after a two-hour rain delay, combining with three relievers on a six-hitter.
Reggie Sanders homered and had an RBI double, and Albert Pujols drove in three runs and scored three times. John Mabry had a three-run homer in the sixth, and Scott Rolen drove in his major league-leading 77th run.
The division-leading Cardinals, who have the National League’s best record at 47-32, have not lost more than three in a row all season. The Cardinals also improved to 9-1 in interleague play with the win.
The Cardinals are hoping to get outfielder Jim Edmonds back into the lineup on Saturday. Edmonds, who has 15 homers and 47 RBIs, didn’t start his seventh straight game Friday as he nurses an injured groin.
“I’m doing OK,” he said. “I swung the bat good and I think I’m doing good.”
Ichiro Suzuki had two hits in Seattle’s first regular-season game at St. Louis. The Mariners lost for the eighth time in 11 games.
The Mariners, who sit in last place in the AL West, have dropped eight of 11 games.