Buster Posey would never admit that he wore down in the second half last season, when his numbers tailed off as the Giants fell out of the race. But Posey didn’t have to say anything on Friday.

The catcher was noticeably more muscular at a media session at AT&T Park, and coaches and members of the training staff couldn’t hide their excitement as the former MVP walked past.

“He looks like he’s been getting after it pretty good,” manager Bruce Bochy said, smiling.

For the first time as a full-time big leaguer, Posey had a regular offseason. The Giants played deep into the fall while winning titles in 2010 and 2012 and Posey spent the months after the 2011 season rehabbing a devastating ankle injury. He said this winter felt long, and it’s not one he wants to repeat, but it allowed Posey and strength coach Carl Kochan to work on a more stringent program. Posey said he has put on about 10 pounds of muscle since the end of the 2013 season.

“I didn’t have to skip any parts,” Posey said. “I feel like I added some good weight. That’s the goal, to be an explosive, powerful player and be able to maintain that during the course of the year.”

That wasn’t the case a year ago. Posey hit .325 with 13 homers, 56 RBIs and a .931 OPS in the first half last season, but after the break he hit just .244 with two homers, 16 RBIs and an OPS of .643.

“I think at times he was tired,” Bochy said, pointing out that Posey caught plenty of long games last summer when the pitching staff struggled. “He wanted a little gas in the tank. Hopefully he can push on that pedal in the second half this year.”

Posey refuses to connect the slump at the plate to all the time spent behind it, but he conceded last September that he wanted to do more strength work. Regardless of how he gets through the grind this time around, Posey needs to be more of a force if the Giants are to return to the postseason.