(Patrick McDermott / Getty Images)

As expected, Ross Detwiler was officially placed on the 15-day disabled list on Sunday afternoon with a low back strain. The roster move is retroactive to Detwiler’s last start on July 4 and the left-hander wouldn’t be eligible to come off the disabled list until July 19.

Dan Haren, who has been on the disabled list since June 23 with right shoulder inflammation, will rejoin the Nationals’ rotation Monday in Detwiler’s place and start in Philadelphia. The Nationals expected to bring back Haren on Tuesday, but because of Detwiler’s injury, he was moved up a day.

The move is no surprise as Detwiler felt stiffness in his lower back earlier Saturday as he threw a bullpen session. Detwiler missed a month earlier this season on the disabled list with a strained right oblique, an injury that appears to be unrelated. But the left-hander may have strained his back overcompensating. In five starts since returning from the disabled list, Detwiler has gone 2-3 with a 6.31 ERA.

Rookie right-hander Taylor Jordan will remain in the Nationals’ rotation and make the third start of his career Tuesday in Philadelphia. Jordan has a 2.70 over 10 innings in his first two career starts.