The Boston Red Sox moved struggling left-hander Drew Pomeranz to the bullpen and will keep left-hander Brian Johnson as a starter after ace Chris Sale returns from the disabled list.

Pomeranz, 1-5 with a 6.31 ERA, is winless in eight starts since a May 2 victory over Kansas City. Pomeranz matched a season-worst mark with five walks in Tuesday’s start at Toronto, leaving after 4⅔ innings.

Pomeranz, who was drafted by the Indians in 2010 and played for the Akron Aeros, has completed more than five innings twice in 11 starts.

Johnson won his second straight start in Wednesday’s victory over Toronto. He’s 3-3 with a 4.00 ERA in 29 games, eight starts.

Sale, who has mild left shoulder inflammation, threw a bullpen session Thursday and is expected to return Sunday against Baltimore.

Boston has the best record in baseball at 81-34. The Red Sox have won six straight, 10 of 11, and 25 of 30.

Rockies pitcher returns

The Colorado Rockies reinstated reliever Chris Rusin from the 10-day disabled list after the reliever missed time with plantar fasciitis.

Rusin went on the DL on July 24. He also missed time earlier this season with a strained intercostal muscle.

The 31-year-old left-hander is 0-2 with a 6.81 ERA in 35 appearances this season. Rusin made a career-high 60 appearances in 2017 and posted a 2.65 ERA.

To make room on the roster, the Rockies optioned right-hander Yency Almonte to Triple-A Albuquerque.

Almonte had a 1.00 ERA in seven games spanning two stints with Colorado since he made his major-league debut June 21.

Strasburg on mend

Washington Nationals manager Dave Martinez said right-hander Stephen Strasburg (cervical nerve impingement) will throw at least one more bullpen session before the team decides whether he is ready for a minor-league rehab.

Strasburg has not pitched for Washington since July 20.