The injury bug may have bitten the Phillies again, in a very big way.

Roy Halladay left his start Saturday against the Cardinals after just two innings of work because of shoulder soreness. Halladay surrendered four runs in the first inning on a grand slam by Yadier Molina. He bounced back to pitch a perfect second inning before leaving the game. The Phillies went on to lose the game 8-3.

"Worried? Yeah, definitely, I'm concerned," Phillies manager Charlie Manuel said. "Pitching is one of the big things on our club and when guys miss a turn, it concerns me."

For the Phillies, it is yet another blow to their season because of an injury. The team has already been without the services of All-Stars Ryan Howard and Chase Utley, who have both missed the entire season so far.

Injuries are a main reason why the Phillies, who have won the last five division titles, sit at the bottom of the NL East, five games behind the first-place Washington Nationals.

Halladay is 4-5 on the season with a 3.98 ERA but has struggled recently. After winning his first three starts Halladay is 1-5 with a 5.08 ERA in eight games, and the Phillies have lost seven of his last eight starts.

It is still unclear how much time, if any, Halladay will miss. "If we have to fill a rotation spot, we'll get somebody and fill it," Manuel said, "the games will go on."