The Red Sox have shaken up their bullpen ahead of Thursday’s series finale against the Seattle Mariners, calling up right-hander Luis Guerrero to the big league roster.

To make room the Red Sox also optioned right-hander Josh Winckowski to Triple-A Worcester. Winckowski threw 80 pitches over three innings in Wednesday night’s loss and likely would have been unavailable to pitch for several days.

Guerrero made his MLB debut last fall and enjoyed a highly successful September cameo, making nine appearances without allowing an earned run to start his big league career. The hard throwing righty, who boasts a fastball that averages 97.5 mph, entered spring training as one of the contenders to start the season on the Opening Day roster, but command issues led to his starting the year in Worcester.

Since then Guerrero has posted a 5.23 ERA with seven strikeouts and five walks over 10.1 innings through his first eight appearances with the WooSox.

Winckowski has appeared in six MLB games this season, posting a 3.86 ERA over 11.2 innings for the Red Sox.