"Carlos Zambrano showed up for his rescheduled MRI, his anti-inflammatory shot and the charter flight to Cincinnati, all in one day.

The Cubs now hope he will show up for a start next weekend in Houston, only two weeks before the beginning of the playoffs.

The MRI on Thursday revealed Zambrano's right shoulder has inflammation and rotator cuff tendinitis, which will take him out of Sunday's start against the Reds and give him as much as 11 days between outings.

"Hopefully, by time we get to St. Louis [on Tuesday] he will throw [in the bullpen]," general manager Jim Hendry said. "If that proceeds in a positive fashion, he will be ready to start, probably by the end of the series in Houston."

"So he'll just be missing, hopefully, this one start. Obviously, he'll have to get his strength back from not pitching. Once the shot takes its proper course, he will begin throwing in St. Louis."

Zambrano left Tuesday night's game before the sixth inning. The Cubs did not believe his injury was serious, although they did nothing to quell speculation it might be. Zambrano already has been on the disabled list in June because of a similar problem and suffered through August with a 7.43 ERA.

"Dr. [Stephen] Gryzlo has been right-on with all his evaluations and he felt [Wednesday] this was not going to be a significant problem," Hendry said. "It was not like [when] he had to be put on the DL after Tampa Bay. And Carlos never felt it was going to be that serious either."

There was no clear explanation why the Cubs didn't temper speculation about Zambrano's problem or why he skipped his scheduled MRI test Wednesday. One report said he had personal business to attend to, another that Zambrano did not want to have an magnetic resonance angiogram (which involves an injection) that might cause him to miss several days.

"He was hoping he wouldn't miss any [time], but once you see some inflammation …," Hendry said.

The Cubs will be missing two-fifths of their rotation in the next few days. Rich Harden, who pitched Aug. 29, won't start again until Wednesday in St. Louis."