Manny Ramirez's trade request will be difficult to honor because of his contract, Boston Red Sox president Larry Lucchino said Thursday. Lucchino also said he didn't know the left fielder's motivation for refusing manager Terry Francona's request to play Wednesday afternoon's game at Tampa Bay after another outfielder, Trot Nixon, was sidelined with a strained muscle in his side. Before the injury, Francona told Ramirez he could have the day off. "It's hard to know if the events of the last couple of days are the result of sort of psychological and physical needs for a sustained period of rest or it's some calculation or some move to encourage us to trade him," Lucchino told WEEI radio on his regularly scheduled segment. Lucchino and Ramirez's agent, Scott Parker, did not immediately return phone calls seeking comment. Team owner John Henry and general manager Theo Epstein did not respond to e-mails, and the Red Sox clubhouse was locked on their day off Thursday. Ramirez is batting .275 with 28 homers and a major league-leading 92 RBI for the Red Sox, who lead the AL East by 1? games over the New York Yankees. He is due $57 million over the remaining three years of his contract. On Tuesday, Sports Illustrated reported on its Web site that Ramirez, for at least the third time in four seasons, had asked to be traded. The report said he told club officials he was unhappy in Boston, especially with an off-field lack of privacy.