Although the conventional wisdom suggests that the Phillies have been struck with an inordinate amount of injuries this spring, just about every major league team emerges from spring training with some sort of health problem.

The Houston Astros just suffered one that could directly affect the Phillies. Lefthander J.A. Happ, who is scheduled to start against Roy Oswalt on Sunday at Citizens Bank Park, suffered a strained right oblique Tuesday while pitching in an exhibition game against Triple A Oklahoma City.

Happ, who strained an oblique in September 2009 while still with the Phillies, left the game after three innings.

"I'm taking an optimistic approach and we'll see how I feel tomorrow," Happ said, according to the Astros' official website. "Hopefully, I got out before anything too serious [happened]. But it tightened up pretty good. I hope I caught it before it gets too serious."

According to the Astros' site, there is no clear-cut replacement for Happ should he miss Sunday's start. Rule 5 pick Aneury Rodriguez or former Seattle starter Ryan Rowland-Smith are the two most likely candidates to join the rotation. Also, Bud Norris or Nelson Figueroa could be moved up in the rotation to face the Phillies.

Happ was part of a three-player deal that brought Oswalt to Philadelphia last year.

- David Murphy