Pat Sullivan / AP

Since Sean Burnett returned from a 10-day hiatus to rest an irritated nerve in his left elbow, he has not pitched to his usual standard. In three appearances totaling five outs, Burnett has allowed five hits and a walk. He hasn’t completed an entire inning.

The problem, he said, is not health. His elbow has given him problems on occasion throughout the season, but the rest served the purpose he hoped it would from health standpoint.

“It’s fine,” Burnett said. “It’s as good as it’s been right now all year. It’s just poor pitches and poor execution. It’s got nothing to do with health, that’s for sure.”

Burnett pitched for about a month with discomfort in his left elbow, the same problem that surfaced shortly after the all-star break. He had begun to favor the injury, which led to changes in his delivery. He did not “get on top of the ball,” which robbed his fastball of sink.

“Now, I’m stuck doing the bad habits,” Burnett said. “It’s just a couple bad habits I need to correct. I need to make better pitches.”

Burnett has been a crucial piece of the Nationals’ bullpen for three seasons, and early this year he was automatic. He and Michael Gonzalez give the Nationals two left-handed set-up relievers, but Burnett can also be dominant against right-handed hitters when he is on. In the final two weeks of the Nationals season, it would be encouraging for Burnett to show he’s back at 100 percent.