CHICAGO -- White Sox reliever Kelvin Herrera exited with lower back stiffness in the eighth inning of Sunday’s 9-2 loss to Boston at Guaranteed Rate Field. He is listed as day to day.

The veteran reliever, who was charged with a career-high five runs in two-thirds of an inning, had just allowed a bases-loaded infield single to Eduardo Nunez when head athletic trainer Brian Ball and manager Rick Renteria came to the mound. Herrera didn’t throw another pitch as he was replaced by Caleb Frare, who then walked Andrew Benintendi on four pitches to force home a run.

“Originally he mentioned his foot and he's had the surgery on it,” said White Sox manager Rick Renteria of the torn ligament in Herrera’s left foot that prematurely ended his 2018 season. “But he said the way he stepped with his foot, he spasmed his back.

“He's day to day right now. We expect it's going to be something very light in terms of injury.”