Pitching coach Ethan Katz says Aaron Bummer’s sinker is ‘most impressive thing’

GLENDALE, Ariz. — Play catch with White Sox left-hander Aaron Bummer at your own risk.

Bummer is one of those lefties who never threw anything straight, something his catch partners over the years can attest to. New Sox pitching coach Ethan Katz found out firsthand last month.

When pitchers play catch with each other, they often stretch the distance beyond 60 feet and throw the pitches in their arsenal on flat ground, for touch and feel.

Katz, 37, said seeing Bummer’s sinker move “was the most impressive thing I’ve ever seen in my life.”

“I was with Aaron early January in Arizona and I had a great opportunity playing catch with him,” Katz said, “and I’ve caught a lot of baseballs with guys that throw really hard. And that was by far, one of his sinkers he threw me, was the hardest pitch I have ever had to try and catch in my life.”

Katz went into defense mode.

“Had it not been off to the side he would have squared me up and hit me,” Katz said. “I was just trying to knock it down.”

Bummer’s sinker averaged 96 mph last season per Brooks Baseball. He also throws a cutter and slider and occasional changeup.

Pitchers and catchers reported to camp officially on Monday, and Bummer had a great excuse for arriving a bit late. He was with wife Amber to welcome the birth of their child.

On Monday, all Sox players will be in camp for the first full squad workout.

Bummer posted a 0.96 ERA over nine relief appearances last season after pitching to a 2.13 ERA in 58 appearances in 2019. He was out from Aug. 7 to Sept. 24 last season with a biceps strain and biceps nerve issue and when he returned, he made four scoreless relief appearances, two of them in the Wild Card series against the Athletics. He is throwing without restriction this spring.

And not throwing anything straight.