Washington, DC -- (Sports Network) - Washington Nationals starting pitcher John Patterson exited Sunday's 10-9 loss to San Diego after the first inning with a right forearm strain.

Patterson missed nearly 60 games earlier in the season because of the same injury.

He threw 31 pitches Sunday, giving up one run on three hits.

Patterson went on the DL April 28 with a right forearm strain and finished three rehab starts 0-1 with a 4.05 earned run average and 13 strikeouts before returning to the majors on June 23.

On the season, Patterson is 1-2 with a 4.31 earned run average. Last year, he wrapped up a career season with a 9-7 mark in 31 starts with a 3.13 ERA and 185 strikeouts.