The Philadelphia Phillies have activated left-hander Ranger Suarez from the 15-day injured list to start Saturday's game against the Kansas City Royals.

Suarez, 28, had been out since July 23 with lower back soreness. A first-time All-Star this year, Suarez has lost four of his past five decisions, last earning a victory June 8.

Suarez (10-5, 2.87 ERA) has yet to face the Royals in his career.

In a corresponding move, left-handed reliever Tyler Gilbert was optioned to Triple-A Lehigh. Gilbert made his season debut Friday, allowing a run in two relief innings during a 7-4 loss to Kansas City.

The Phillies have lost four of their past five games but still hold a five-game lead over the Atlanta Braves in the National League East.

Field Level Media contributed to this report.