Some nuggets from Jon Meoli's 'Inside the Dugout' Banner email:
The risks in signing a slugger in his 30s didn’t materially change in the ensuing year. But a foundation Alonso built over that offseason, his first working with Diesel Optimization in Tampa, Florida, didn’t just set Alonso up to perform as well as he did in 2025.
It introduced Alonso to a program that, combined with the mindset that has made him among the game’s most durable and consistent performers, can possibly eliminate that risk by giving him a new understanding of himself as an athlete and a hitter.
“Pete walked in the door … open to learn," he said. “I think that’s what makes him great, is that he’s always going to try to be the competitor, he’s always going to try to win, and I think that’s the biggest thing I’ve seen in 20 years working with these top-caliber guys is, man, when you get these guys that want to work and learn and don’t want to lose, then here we go.”
Assessments at Diesel cover everything in a player’s life, from strength and swing breakdowns to sleep and dietary habits. Typically, the adjustments aren’t major. Wallin raved about Alonso’s strength, discipline and commitment to his program, right down to a daily 6:30 a.m. run for three months straight.
The movement and swing work seemed to unlock new levels of power for Alonso in 2025, though. Wallin likened it to keeping a Ferrari in alignment, which in Alonso’s case meant better alignment in his hips so he could establish the base of his swing more naturally.
That physical base allows a hitter, particularly one as strong as Alonso, to better express his power, and the cues to feel what the best version of it are allow them to focus on how they’re being pitched.
“That seems to be the equation that’s been working a long time with a lot of elite people,” Wallin said.
Several data points illustrate the impacts of that work. According to MLB Statcast, Alonso’s stride length was over 3 inches shorter, on average, in 2025 compared to 2024, and his back foot shifted less and remained square through contact.
Alonso has been back this winter pursuing those same improvements, armed with a year of experience in the program. He came back to Diesel emphasizing areas he wanted to improve in and is dedicating hours each day to those goals.
“His mindset is so strong, and he’s so disciplined, and he wants to be great,” Wallin said. “The difference is it won’t waver. The only difference between Pete and a minor league guy is Pete’s mindset is he’s going to do everything it takes, every day. The Polar Bear is going to continue to push and continue to push. … He does things every day for hours to get his body back, every day, to be able to hit homers. The cool part is some athletes don’t have that mindset, but he does, and that’s why he’s elite, and he’s going to continue to be elite.”
