Ian Browne
@IanMBrowne

BOSTON -- After another mid-game malfunction in the bullpen in Sunday’s 12-4 loss to the Rays, the Red Sox designated struggling relievers Hirokazu Sawamura and Austin Davis  for assignment, a source told MLB.com.

When the Red Sox open a three-game series in Minneapolis on Monday night, righty relievers Zack Kellyand Kaleb Ort will be added from Triple-A Worcester to fill the open spots on the roster.

The Red Sox have struggled all season in the bullpen, as evidenced by a 4.54 ERA, which ranks 27th in the Majors.