Pettitte, 38, continues to decide between pitching another season and retiring to spend more time with his family. But he wanted to offer his support for the pursuit of another free agent left-hander.
"He wants us to get Cliff Lee, I can tell you that," Cashman said. "He's still going through the personal decision-making. He's not retired. He has not made a decision to retire.
"He may be leaning one way or the other. He's gone into the process thinking this might be the winter he might."
While both Cashman and manager Joe Girardi thought Pettitte left the Yankees in October more serious about retirement than ever before, they still want to believe Pettitte will be back on the mound in 2011.
"I didn't hear him say that after the 2009 season, so I think it's something that he's probably considering a little bit more," Girardi said. "Whatever he decides to do, he's had a tremendous career. He's been a great Yankee. If he decides that this is his last year, we're really going to miss him. But if he doesn't, you know how we all feel about Andy."
Perhaps it's best to put it this way -- until the day Pettitte doesn't come back, they have to believe he will.
"If I had to bet at some point, I think he'll play," Cashman said. "He's telling me right now he's leaning the other way. He just doesn't want to hold us up. He's wrestling back at home.
"He's a Yankee for life, whether he's a player or not. He cares about everything we do. He wants us to get Cliff Lee if we can get him, and he doesn't want to interfere."
Cashman said Pettitte knows that the Yankees are hoping he returns for another season, and said that Pettitte would make any rotation better. But if Pettitte is going to actually put the pinstripes back on, it will take more time.
"I wouldn't be surprised if he gets there," Cashman said. "That's what always happens. But this winter is going to take longer if he gets there."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.