Have the Four Philadelphia Aces Become Three?

Pitcher Roy Oswalt was pulled from Thursday night's game against the Cardinals after only two innings, in which he allowed four runs.

After one out in the second, Oswalt began teetering sideways off the mound after his delivery.  Things got worse as the inning went on, as Oswalt began hopping and stumbling after pitches while grabbing his lower back.

Oswalt was left in to finish the inning.  Afterward, reports were that Oswalt had back spasms.

Later, Oswalt told MLB.com reporter Austin Laymance, "At this point I'm not really helping the team, I'm kind of a liability more than anything."

He also added that his back has been hurting lately upon sitting, standing, walking and sleeping.  That is very bad news.  And why Oswalt was allowed to make this start under these circumstances is curious.

However, the back issues are not really a surprise.  Oswalt had a long history of back problems before he came to the Phillies last season.  He has also been on the DL once already this year with the same issue. 

In his last four starts, Oswalt has allowed 15 runs in only 21.1 innings.  And now, it appears he is headed back to the DL, possibly for a long time.

The four aces have essentially been cut down to three without Oswalt, leaving Roy Halladay, Cliff Lee and Cole Hamels as the remaining top starters.  The original fifth starter, Joe Blanton, is also on the DL and there is no date set for a possible return.

The Phillies can fill the holes with younger pitchers like Kyle Kendrick and Vance Worley.  However, the long-term effect on the Phillies season is a big question mark.

And another question is whether Oswalt will be back to pitch this year.  And if he does return, how effective will he be after multiple back injuries?

An MRI on Monday should provide more details, but for now, the Phillies are in a potentially bad spot without one of their aces.