The Phillies are unlikely to look to use a pitcher who they would have to add to the 40 man roster. That would seem to knock out much mentioned Adam Bernero who recently signed a minor league deal and is pitching well at AAA Scranton Wilkes-Barre. While he's got major league experience - 10-6, 5.91 in 146 major league games - he hasn't had a lot of major league success and adding him to the 40 man roster would likely turn out to be a waste of a spot. That would also take out Reading's Giovany Gonzalez.
One Reading pitcher who could be considered is Scott Mathieson. The 22 year old right-hander is on the 40 man roster and is pitching well at AA Reading, although his last start was shaky. He last pitched Sunday, putting him in perfect position to make the start if the Phillies did decide to go that way. Mathieson is 6-2, 3.05 in 13 AA starts for Reading this season and should be in line for a promotion at least to Scranton in the near future. A once and done audition with the Phillies might be an interesting possibility for Mathieson.
At Scranton, there's our old buddy Gavin Floyd. This is the kid who was timid and over matched at the major league level, but has gone 1-0, 1.69 in two starts for Scranton since being demoted when his 7.29 ERA in the majors simply became too much for the Phillies to handle. Like Mathieson, Floyd pitched on Sunday and would be in the perfect spot to handle the start if the Phillies decided to go that route. Floyd's teammate, and fellow demotee, Eude Brito isn't an option. He's scheduled to start Tuesday night for Scranton and he also hasn't been back in the minors for the required ten days since being demoted from the Phillies.
Perhaps the guy most wanting the job is reliever Ryan Franklin. This is a guy who has been a starter in the past, but has been working out of the Phillies' bullpen this season. As recently as a couple weeks ago, Franklin insisted that he could likely give the Phillies four or five good innings as a starter. He hasn't been consistent in the bullpen and perhaps a turn in the rotation would help to straighten him out and also possibly generate some interest in him from other clubs looking for a guy who could move into the rotation. Franklin could be the odds on favorite to get the start, with either Mathieson or Floyd a possible fall-back consideration.
The Phillies may consider sending outfielder Chris Roberson back to AAA Scranton. His roster spot might be better suited for another reliever should Franklin make Saturday's start or for a middle infielder who could relieve Jimmy Rollins and Chase Utley here and there. Danny Sandoval and Angel Chavez are both on the 40 man roster and could be options. Joe Thurston and Bobby Scales are putting up nice AAA numbers, but neither are on the 40 man roster, which doesn't help their chances.