Nationals starter Stephen Strasburg lasted just four innings Sunday, departing from an eventual Washington victory with discomfort in his upper back, per MASN Sports.

Strasburg was not as sharp as he had been in previous starts, allowing four runs and seven hits, including two home runs over just 60 pitches. He had won three of his previous four starts in August since returning from the disabled list. 

Strasburg is 8-6 this season with a 4.35 ERA.