(Katherine Frey/TWP)

As Stephen Strasburg finished off his first complete game Sunday night, Manager Davey Johnson and right fielder Jayson Werth sat next to each other in the trainer’s room. “We were in there sharing tables in the eighth inning,” Johnson said. “He had more ice on him than I had heat on me.”

Both Johnson and Werth left the Nationals’ 6-0 victory over the Phillies, and both should be fine to return Tuesday when the Nationals open a series against the Giants. Werth jammed his right knee sliding into home in the fifth inning, while Johnson left the dugout in the seventh inning with lingering back pain that will require a procedure Monday.

In the fifth, Werth led off with a single and eventually reached third base. He ran home on Wilson Ramos’s grounder to second base and slid into home plate as Chase Utley’s throw bounced home. He limped away from the plate, but remained in the game.

In the sixth inning, Werth singled again – his third hit of the game – and stayed into run the bases. After the inning, Roger Bernadina replaced him in right field. Team physician Dr. Wiemi Douoguih examined Werth, but the tests revealed only a bruise.

“It’s okay,” Werth said. “It just kind of got caught up underneath me in that slide into home. It kind of stiffened up a little bit. I didn’t think it was a big deal. It should be okay with the day off tomorrow. I’m sure we’ll know more when I wake up in the morning, but I don’t think it’s a big deal.”

The Nationals need Werth to be healthy. After Werth went 3 for 4 with three singles, he raised his slash line to .328/.401/.530. If he had enough at-bats to qualify, Werth would rank third in the National League in batting average, third in on-base percentage and fifth in slugging.

Johnson has dealt with pain in his lower back to some degree all season. It worsened Wednesday, and struck again today. He considered leaving the dugout in the sixth inning. In the seventh, with the Nationals ahead six runs, he decided he would retire to the trainer’s room to receive heat treatment on his back.

“I told them, ‘If you guys mess this up, come and get me. I’ll be down,’ ” Johnson said.

Monday, Johnson plans to receive an epidural injection to ease the pain. Johnson underwent a similar procedure at the end of last season, when he left the Nationals’ final home game early with similar back pain.

Sunday, Johnson left bench coach Randy Knorr in charge as Strasburg neared the first complete game of his career.

“I didn’t want to be the one who had to take him out,” Knorr said, laughing.