Tension flared between Mets reliever Frank Francisco and the Nationals late in the Nationals’ 7-2 victory Thursday afternoon after Francisco drilled Jayson Werth with a pitch. As Francisco insisted he had not hit Werth on purpose, the Nationals expressed angered skepticism.

“Who the heck knows?” Manager Davey Johnson said. “We don’t know what’s going on. He was wild. The ball was going all over the place. But I thought our guys handled it well. We didn’t overreact to it. That guy is a little goofy out there, anyway. He was looking over at our bench and chatting at our bench. It’s a good thing we don’t see them again.”

With no outs in the eighth inning, after he allowed two doubles to start the inning, Francisco moved to a 3-0 count on Werth with three splitters. Francisco hit Werth in the middle of the back with a 93-mph fastball.

Werth yelled at Francisco. Home plate umpire and catcher Anthony Recker moved between Werth and Francisco. The benches never emptied.

“He can say whatever he wants,” Francisco said. “I was trying to locate my pitches and obviously I was all over the place.”

When asked about the pitch, Werth replied, “I’m not going to comment on that.” Other Nationals were not convinced Francisco had simply lost control.

“Didn’t want to pitch to him,” one Nationals player said. “Scared.”

Werth, who entered the day leading the National League in OPS, had gone 0 for 3 with three strikeouts before he came to the plate. Mets Manager Terry Collins considered Werth’s rare off day evidence that Francisco had made a mistake.

“There might have been something in the past that I’m not aware of,” Collins said. “But Jayson wasn’t having the best of days so certainly I don’t think we hit him on purpose. We didn’t have a lot of chances to get outs and today was one of those days where he wasn’t swinging very good and we could get him out, so I don’t think it was intentional, no.”

The pitch left Werth with a red welt on his left shoulder blade. It may have hurt Francisco’s reputation.

“That was total B.S. what Francisco did there,” one scout at Citi Field said. “Almost got his shortstop’s ankle broken.”

After Werth walked to first base, Harper followed with a grounder to second. Werth slide hard into shortstop Ruben Tejada, breaking up a double play. When Ian Desmond followed with another grounder, Harper barreled into second baseman Daniel Murphy, which broke up another twin killing and allowed Zimmerman to score.

“The second baseman knew they were coming,” Johnson said. “That’s just good baseball.”