The Phillies are walking a fine line between getting perhaps the best pitcher in baseball and keeping their farm system as intact as possible.
The Toronto Blue Jays had officially asked for Kyle Drabek, J.A. Happ, Dominic Brown. The Phillies are trying to swing a deal with Toronto without having to give up both Happ and Drabek in the deal.
For their part, Toronto is looking to stock up on young pitchers if they're going to give up Halladay in a deal.
The Dodgers and Angels have also received lists of players that the Blue Jays would like in a deal for Halladay and the Angels are supposedly very interested in making a deal to get Halladay. Even with the Dodgers and Angels in the running, the Phillies are considered to be front-runners because of their strong farm system.
Phillies GM Ruben Amaro would consider a deal where Carlos Carrasco was substituted in the package of players for either Happ or Drabek. For the Phillies, they would like to see Toronto accept Happ, Carrasco and Brown for Halladay and it's uncertain whether not including Drabek might kill the deal.
The other option would be to convince Toronto to include either infielder Marco Scutaro or reliever Scott Downs in the deal if the Phillies were to include both Happ and Drabek in the deal.