"He's got some stuff that he can work on but he needs to have some success so he can start getting a better feeling," manager Tony La Russa said. "He was handling it great, but at some point. ..."
Reliever Todd Wellemeyer will take Reyes' spot in the rotation Wednesday at Colorado. The Cardinals recalled left-hander Troy Cate from Memphis to fill the roster spot.
Wellemeyer, 28, was claimed off waivers from the Kansas City Royals on May 15 and has a 2.70 ERA in four appearances with St. Louis, striking out eight and allowing two earned runs in 6 2/3 innings. He'll be making his first career start, which doesn't concern the Cardinals.
"I don't even know, but we like the possibilities, so he gets it," La Russa said.
La Russa compared Wellemeyer, who had a 10.34 ERA in 15 2/3
innings with the Royals, to Braden Looper, a converted reliever who is 6-3 with a 3.10 ERA in his first starting experience since his first year in the minors in 1997.
The difference is that Looper was able to build stamina during spring training.
"He reminds me a lot of Looper, because they're both big and strong," La Russa said. "This is not like Looper in a sense he doesn't have six weeks of spring training.
"This is a tough way to get introduced into the rotation."
La Russa said he did not consider Ryan Franklin, the primary setup man after competing for a starting job in spring training, for the opening.
Reyes is 0-8 with a 6.08 ERA in nine starts and allowed five runs and eight hits in 5 2-3 innings in a loss to the Nationals on Friday. He was 5-8 with a 5.06 ERA as a rookie last year, but made a name for himself with eight dominating innings against the Tigers in the Series opener.
Reyes, 25, is the first Cardinals pitcher to lose 10 straight decisions since closer Dennis Eckersley lost 10 in a row from April 4, 1996 to Aug. 26, 1997. Team records going back to 1957 show no starters with losing streaks of that length.
La Russa said Reyes, who had been considered the team's top pitching prospect before last season, wasn't visibly upset. He was 6-1 with a 2.57 ERA and 82 strikeouts in 84 innings for Memphis in 2006.
"He didn't have a lot to say," La Russa said. "He listened and I tried to explain that he's an important guy in our plans and I expect to see him back."
Cate, 26, was 1-3 with a 4.54 ERA in 13 games at Memphis and is in the majors for the first time after impressing the team in spring training. His last seven appearances have been as a starter, with a 1-3 record and 5.40 ERA.