The Dodgers have placed Clayton Kershaw on the 10-day disabled list with a lower back strain, the team announced.
Dodgers manager Dave Roberts said he expects Kershaw to be out for at least a month. A MRI showed no "structural damage" to the disks in Kershaw's back.
Kershaw returned from the DL on Thursday night against the Phillies after missing a month with biceps tendinitis. He lasted only five innings and exited the game with back tightness.
The Phillies mustered one run and four hits off Kershaw en route to their 2-1 victory. Kershaw threw 42 of his 62 pitches for strikes. The lefthander's fastball was clocked in the high 80s, noticeably lower than the 92.1 mph he's averaged this season.
Back injuries have sidelined Kershaw over the past two seasons. He missed five weeks last season with a lower back strain and suffered from a herniated disk in 2016 that forced him to go more than two months between starts.