Ross Detwiler will miss another month because of an issue with a disk in his back which is pinching a nerve and causing back spasms Manager Davey Johnson said after Wednesday’s game. The left-handed starter is slated to receive an injection in his back and will not require surgery Johnson said. The Nationals sent Detwiler to Los Angeles on Monday to receive a second opinion from well-known back surgeon Robert Watkins Sr.

“He’s got to rest it” Johnson said.

The Nationals have been concerned with the left side of Detwiler’s lower back which hasn’t improved since he was sidelined and placed on the disabled list July 4. Detwiler threw a bullpen session on July 19 but it was an abbreviated session because of the back discomfort.

The news although not unexpected given the lack of improvement in Detwiler’s back deals the Nationals a significant blow. They have patched up the back of their rotation with rookie right-handed starter Taylor Jordan but he is about 20 to 30 innings away according to Johnson from reaching his innings cap in his first full season back from 2011 Tommy John surgery.

Detwiler hasn’t been the same since he returned from a strained oblique in his right side. He posted a 2.76 ERA in his first eight starts but in five starts since his return from the disabled list because of the oblique injury he has punched up a 6.31 ERA. The back end of the Nationals rotation including Dan Haren and his 5.79 ERA have been a major issue and could force the team to continue exploring adding a starting pitcher via trade.