Yoenis Céspedes' offseason workouts left him 15 pounds heavier and just might help prevent some of the nagging injuries that might have led to his sophomore slump. Céspedes' trainer, Adam Brush, said by phone from Boca Raton, Fla., that they worked on improving areas where Céspedes had injuries that affected him throughout last season, especially his shoulders and hamstrings. In addition, grip strength work should help prevent the hand injuries Céspedes has been prone to get his first two seasons. "It's no secret he had some hamstring and shoulder issues that didn't go away," said Brush, who worked in close conjunction with the A's training staff during the winter. "So we did a lot of stability work for the shoulders, and for hamstring strength, he was pushing, pulling, dragging, flipping 400-pound tires. But we were very careful not to overwork him - let's get healthy and feeling good." The problem areas now? "Nonissue," Brush said. "Everything was smooth with Yoeni." Céspedes said in English on Thursday that flipping tires was "very hard," but good for his legs. He hopes that all the work will eliminate his injury issues, which probably contributed to his .240 batting average last year, down from .291 in his rookie season. Céspedes also said he plans to cut down his swing to make more consistent contact; the extra strength he's gained might help counter any loss of power from a shorter stroke. "He's such a strong physical specimen, a machine, but you want optimal strength for what you're doing," Brush said. "At some point, you don't need to be strong, you don't need to be bigger. And he's so strong, even with shortening his swing and even if he mishits the ball, there's still a chance he'll hit the ball off the wall. Or over it." "You don't need to worry about Cespy's power," hitting coach Chili Davis said. "If he squares the ball up more consistently, you know he's going to hit the ball out more often. For him, it's just a matter of approach." Davis was trying to get Céspedes to shorten his swing a bit last year, but the main thing for the slugger, Davis believes, is focus: Céspedes needs to be as focused all season as he was during the playoffs, when he hit .381 with a 1.076 OPS against an extremely tough Tigers pitching staff. "I like where he is mentally," Davis said of Céspedes' work the first week of camp. "He told me he has no numbers for goals except creating good contact off the bat." So far, so good, though Davis wants to see Céspedes put his shorter swing into action in a game before he really can critique it. His one concern is that Céspedes might be vulnerable to pitches away, but he believes Céspedes can adjust. And if all goes as Davis suspects with Céspedes' third season in the major leagues, "You might see something you've never seen before." Brush, who worked with Céspedes four days a week this winter at the Institute of Human Performance, expects that Céspedes will drop some weight over the course of the spring and season, anyway, and will go from 225 back to his normal 205 to 210.