The Red Sox bolstered their bullpen ahead of Friday’s series opener against the San Diego Padres, promoting hard-throwing left-hander Bailey Horn.

The move came a day after the club optioned struggling right-hander Isaiah Campbell to Triple-A. This will be Horn’s first stint in the big leagues.

Originally a fifth-round pick out of Auburn in the 2020 MLB Draft, Horn was acquired from the Chicago White Sox for cash in late April. The 26-year-old boasts a fastball that touches 98 mph, which Red Sox manager Alex Cora cited as his best weapon when asked what he brings to the table.

Red Sox acquire hard throwing left-hander from White Sox

"The fastball, it's a good one, he's been throwing strikes too," Cora said. "With them they've got a bunch of lefties and switch hitters so it makes sense to go this route."

Since joining the Red Sox organization Horn has appeared in 12 games with Triple-A Worcester, posting a 1.69 ERA over 16 innings. Prior to that he'd struggled over his first month with the White Sox Triple-A affiliate, allowing 13 earned runs over 10.1 innings, giving him a 5.47 ERA on the season overall between the two organizations.

Horn will wear No. 78 with the Red Sox.