"He's the total player," Yost said. "He's offensive, he's defensive, he's got leadership skills. But there are still things that he needs to do to continue to get to the next level. I think he's going to be the best. I don't think there's going to be anybody better than him.
"There's only really one that's better for me right now and that's Yadier Molina. There are guys that are good -- [Buster] Posey's like Sal, he's really good and he's won an MVP. He's in the other league and I don't see him enough, but I've always been impressed with Yady. When Sal came up, I saw so many similarities with Yadier Molina's game when [Molina] first came up."
Perez came into this season with a composite .301 average, 139 RBIs and 81 extra-base hits in his 253 Major League games. Yost sees some room for improvement at the plate.
"He could take a few more walks. What happens with good hitters is they have to learn to take their walks. Prince Fielder, that's what turned the corner for him," Yost said. "When you're swinging at pitchers' pitches in situations, you're not helping yourself, you're not helping your team. But if you're staying in your approach and hitting your pitches, you're going to be far more successful, you're going to be on base more. And any time you get on base more, there's an opportunity to score a run. You can't score a run when you swing at a ball and make an out."
Perez is a good contact hitter, with 110 strikeouts in 933 at-bats coming into this season. But he'd drawn a modest 40 walks.
"It's just plate discipline, he'll grow into it," Yost said. "You can't just sit a guy down and say, 'I want you to take more walks.' They have to learn how to do it. And they do it through experience and do it through time."
A reporter mentioned that Molina, a five-time All-Star and six-time Gold Glove Award winner with the Cardinals, sometimes seems to be on another planet.
"Sal can be on that planet, too," Yost said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.