Mariano Rivera was offered a $45 million, three-year contract to stay with the New York Yankees. Now, the team is waiting to hear back from its star closer. “He’d be by $4 million a year the highest-paid relief pitcher,” Yankees senior vice president Hank Steinbrenner said Tuesday. “To say that’s a strong offer would be an understatement.” On Monday, the Yankees retained catcher Jorge Posada when…