Gary Sheffield believes that Alex Rodriguez is destined for the best year of his Yankees career. Sheffield, now with the Detroit Tigers, said Monday that A-Rod is heading into the 2007 season with a clear mind, finally having unloaded the mounting stress of concealing his fractured relationship with shortstop Derek Jeter. "I guarantee you one thing, and I say this right now: Alex is going to have the best year since he's been [with the Yankees]," Sheffield said. "I think what he did, stood up, that's what's going to get him over the top. He expressed how he felt. He was honest, and that goes a long way. I guarantee you, when he went home, it was a peaceful night." Last month, Rodriguez admitted to reporters that he and Jeter are no longer as close as they used to be.