PHOENIX -- Stephen Vogt reached the big leagues on the strength of his bat, but his chances of staying there with the Brewers depend on the strength of his right arm. He has a little black bag in his locker filled with the tools he hopes will help.
Over the offseason, Vogt joined a growing group of position players using weighted balls to improve his mechanics and arm strength. Pitchers like the Indians' Trevor Bauer and Orioles' Zach Britton are known for employing the heavy rubber balls as part of their throwing programs, but position players including Bauer's teammate Francisco Lindor and the Mets' Yoenis Cespedes have found them helpful as well.
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Vogt aims to reverse a process of decline that began several years ago, when he found himself rushing throws in the wake of some early-season stolen bases. Slowly, bad habits took hold, culminating last season after the waiver wire took the two-time Oakland A's All-Star to the Brewers. Vogt threw out four of 31 baserunners with Milwaukee.
"You think you're making a correction that's going to help you, but in the long run it ends up being detrimental and counterproductive," he said. "Next thing you know, you look up and you're like, 'Wow, that's not even me.' I looked at some video and it was, 'Who is that guy?' Arm slot all over the place.
"I feel really good about where I am right now."
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Vogt reaches in his locker for the bag containing his new toys. They are soft rubber balls in different colors and weights up to 2 kg, or about 14 times heavier than a standard five to 5 1/4 ounce baseball.
"What it does is, your body is not going to let you throw something heavier than a baseball incorrectly," Vogt said. "You are going to get your arm in the right spot. You are going to get back on line. It helps you build up your arm strength correctly."
Vogt picked them up in November from the same company associated with Bauer. Vogt's arm feels "good and strong and back to where it was," but he'll need some live action to better judge whether the program worked.

Manager Craig Counsell and the Brewers' coaching staff will have an eye on the results. For the second straight year, the club has three catchers vying for two spots: Primary catcher Manny Pina plus Vogt and Jett Bandy. Vogt re-signed with Milwaukee on Dec. 1 to avoid arbitration -- and a potential non-tender. His contract is non-guaranteed, so the Brewers could opt to release him before Opening Day and owe only a portion of his salary. Bandy, meanwhile, is out of options.
"Manny's on the team. That's where we're at," Counsell said. "Stephen, we brought him back, signed him to a contract, but I think he's got something to prove, and that will be part of his camp. [Bandy being out of options] factors into it. I think we signed Stephen with the idea that we're going to see if -- look, the defense is important for Stephen. We have to see what that looks like."
Is Counsell encouraged by what he's heard from Vogt so far?
"Stephen confronts things pretty head-on," Counsell said. "I think he opens himself up for really honest communication. He understand this. He believes it is something that needs to improve, so he has worked really hard at it."
Vogt is not expecting to morph into Ivan Rodriguez in one offseason. But he does believe the program will make a difference.
"I don't know exactly what it's going to look like in the season, but I'm going to continue doing it in the spring and figure out how I want to implement it," Vogt said. "It's not for everybody. It's not like this is the answer. But for me, being a 33-year-old catcher, it's something that I believe has helped.
"If you stop working, you're going to be done. That's the bottom line."