Jack Curry of the YES Network posted this message on his Twitter account today, which seems to indicate the Phillies are interested in any starting pitcher, not just Pedro Martinez:
Spoke to baseball official who has regular contact w Phils. He said they are itching to add a starter and would love to get Cliff Lee back.
In 12 starts for the Phillies last year, Lee went 7-4 with a 3.39 ERA. They dealt him to the Mariners for three minor-leaguers in December.