Jurrjens landed on the disabled list on August 6 with a right knee strain and has struggled to a 1-2 record in three starts since his return on August 17.
On Tuesday night, he allowed six runs and three homers over six innings in a 9-2 loss to the Nationals. He underwent an MRI Wednesday, which showed no structural damage.
Jurrjens is 13-6 with a 2.96 ERA this season, but is just 1-3 with a 5.88 ERA in seven starts since the All-Star break. He is expected to miss his scheduled start on Sunday against the Dodgers.