The Cubs are offering standout prospect Javier Baez and established shortstop Starlin Castro in an attempt to land Phillies prized pitcher Cole Hamels, a team executive has told ESPN.com senior baseball writer Jayson Stark.

Stark added, however, that the Phillies are not enthralled with either player. But the Cubs remain determined in their efforts to trade for Hamels.

"I don't think they'll be in the rental market," the executive who has spoken to the Cubs told Stark. "So the value to them, with Hamels, is the three years [left on his contract]. This isn't just about selling out to go for the wild card. It's about getting ahead of [the free-agent ace market] this winter."