VIERA, Fla. — Mike Pelfrey pitched four innings, giving up four runs on three hits and two walks in the Mets’ 6-5 loss to the Nationals on Thursday.

“One thing I was really, really upset with was the walks,” Pelfrey said. “That’s the one thing that absolutely drives me nuts, is walking people in spring training. I walked two guys today, so obviously I’m pretty upset about that.”

Pelfrey was hit in the leg with a line drive by Ivan Rodriguez, but stayed in the game, retiring the next 10 batters he faced.

“It got me right above the knee in the quad,” Pelfrey said. “Last year I took one off the bone and it put me out for three or four days. This one got me in the meat part of it, so I should be fine tomorrow. No big deal.”

Lucas Duda, in the mix to replace Carlos Beltran in right field if needed, hit a three-run homer in the ninth.

Chad Gaudin pitched five scoreless innings, and Jayson Werth and Adam LaRoche each drove in two runs for the Nationals.

Gaudin, a non-roster invite to spring training, allowed four hits while striking out six. In two previous starts, he allowed seven runs and eight hits in six innings.

Werth returned to the lineup a day after sitting with what was described as general tiredness in his legs. He had a hit and two walks.

LaRoche hit a two-run double and Rodriguez had an RBI for Washington.