Unpredictable: Marquis has 12 wins but little consistency

~ The right-hander will throw tonight against the Reds.

ST. LOUIS -- From one start to the next, Jason Marquis keeps the St. Louis Cardinals guessing.

The right-hander is among the league leaders with 12 wins, but twice has given up double-digit runs and is saddled with a 5.68 ERA. His next stab at establishing consistency comes tonight in Cincinnati against Eric Milton.

"I go out there every time and try to compete," Marquis said. "Some days you have it, and some days you won't."

There have been several days when he's had it.

Marquis (12-8) teamed with the bullpen to halt Jimmy Rollins' 38-game hitting streak in April. Four times he's worked eight or more innings. He won five straight starts from May 13-June 4.

Then there are those other days, the days that jack up that ERA.

On June 21, the day after Mark Mulder gave up nine runs in 2 2/3 innings while pitching with a shoulder injury that landed him on the disabled list for an extended stay, Marquis was asked to rescue a weary bullpen. He failed miserably, allowing 13 runs in five innings.

It happened again on July 17, a day after Jeff Weaver lasted only four innings in a 15-3 loss to the Braves. This time, Marquis allowed 12 runs in five innings.

It happened a third time on Wednesday, a night after the Cardinals used eight pitchers in a 16-8 loss to the Phillies, and this time a strong finish compensated for a shaky start. He allowed four runs in six innings, throwing 118 pitches in an 8-1 loss that extended the Cardinals' losing streak to seven games. The streak reached eight before the Cardinals won weekend games against Milwaukee.

"If he'd have had worse results we could have had a lot tougher night than we had," La Russa said. "He had a lot of guys on base and he didn't give in to it. He kept competing, which I think is very important."

Marquis' mission in his last start was damage control.

"There were points in the game where it could have gotten out of hand, and I was able to eliminate that somewhat," he said. "You know, it's just a battle out there."