Hamels, 13-7 with a 2.62 ERA, complained of a tired arm after going only five innings and 88 pitches in his last start, a 4-2 loss to the Washington Nationals. The Phillies are hoping that he can avoid a trip to the disabled list by skipping his next outing.
With Hamels temporarily out of the mix, Roy Oswalt will pitch Friday in the opener of a three-game series at Washington. Kyle Kendrick will start Saturday and Roy Halladay will go Sunday for the Phillies, who entered play Tuesday leading the National League East by 8½ games over Atlanta and have the best record in baseball at 78-41.
In other Phillies injury news, third baseman Placido Polanco told reporters that he expects to go on the disabled list Wednesday because of a sports hernia. Since Polanco last appeared in a game on Aug. 6, the disabled list visit can be backdated so that he's eligible to return in five days.
Polanco probably will need surgery, but is hoping to play through the injury and postpone the procedure until the offseason.
Pete Orr, who's hitting .273 in 62 games for the Phillies' Triple-A Lehigh Valley farm club, is a top candidate to fill the void on the roster when Polanco goes on the disabled list.
Senior writer Jerry Crasnick covers Major League Baseball for ESPN.com.