Trea Turner went 0 for 13 against the Phillies over the weekend. (David Zalubowski/Associated Press)

BALTIMORE — Trea Turner was sitting in front of a computer by the entrance to the visiting team’s clubhouse at Camden Yards at around 3:35 p.m. Monday afternoon. He was slouched over, staring intently at the monitor, watching his at-bats from over the weekend in Philadelphia. He was trying to figure out what went wrong.

Turner has not confronted much failure (by baseball standards) since arriving in Washington for good last season. But he stumbled at the plate in three games against the Phillies, going 0 for 13 with six strikeouts and a walk. Manager Dusty Baker decided the uncharacteristic performance warranted a chance to hit the reset button so he didn’t include his starting shortstop and leadoff hitter in Monday’s lineup against the Orioles. Baker called it “a mental day.”

“It just looked like his concentration and everything just wasn’t the same,” Baker said. “I could tell he was starting to worry a little bit. You hate to have him take it off in this series, but you’ve got to consider the long run and the payoff.”

Turner, however, did play a role in Washington’s 6-4 loss to the Orioles. He entered the game in the ninth inning to pinch-run for Matt Wieters at second base as the tying run when pinch-hitter Brian Goodwin hit a groundball to the first baseman. Turner dashed for third base not realizing Adam Lind, the runner on third base, didn’t go home. Turner wound up caught in a rundown that ultimately led to Lind getting tagged for the game’s final out.

“I saw the infield back,” Turner said. “Knew Goodie was up and saw the ball hit to the right side. I figured we’d move up. But [third base coach Bobby Henley] told me before the play I was supposed to keep my eyes on Adam and I had been watching the ball to see if it had gotten through and if I could score. I got a little ahead of myself and caused the situation.”

That was the extent of Turner’s action. A few hours before first pitch, he said he always tries to talk himself out of idle days because they mean he isn’t playing well, which he said, “is never fun for the ego,” and because he depends on feel. He explained he’s not one to talk about hitting and apply the discourse to his at-bats. He prefers pushing through it and experiencing an at-bat where it — whatever “it” is — clicks and he finds a rhythm. But he had started 14 straight games since coming off the disabled list and said he understood the rationale.

“A mental day to relax a bit might not be the worst thing in the world,” said Turner, who already has a cycle under his belt this season. “I always want to play, but I’m young and still learning.”

Turner said he learned something during Monday’s video session: He gave Phillies pitchers the leeway to throw him more off-speed junk because he didn’t capitalize on fastballs as he usually does. When they did that, he swung at bad pitches. The formula resulted in his batting average dropping from .316 to .270 in 72 hours.

“There were probably five, six, seven fastballs last series that I either fouled off or popped up,” Turner said. “If I put those balls in play, either on the ground or hard line drives or I just hit them a little bit better, that’s huge for me. If I got five or six hits on seven, eight fastballs then I had a great series instead of a terrible one. So it’s just a matter of hitting those pitches and not missing.”

Turner said he usually hits on the field and does his normal work even on days off, but he planned to do as little as possible Monday. He never likes not playing, but he’ll back on the field Tuesday ready to start anew. And the Nationals need him. A couple weeks ago, they had a couple of standout leadoff hitters and Baker was bouncing between the two atop the order. Then Adam Eaton was lost for the season. Now they’re down to Turner to spark the offense.

“I think a lot of times I know what I’m doing so I can easily — not easily correct it, but make an effort to correct it,” Turner said. “Right now I’m just a little off. I don’t think I’m taking bad swings. I just think it’s decision-making. So more so just relaxing and getting back into the groove.”

● Koda Glover and Shawn Kelley both threw off a mound Monday afternoon at Camden Yards. It was the first bullpen session for the co-closers since they each went on the 10-day disabled list.

Kelley landed on the DL Friday — retroactive to May 2 — with a lower back strain. The Nationals can activate him Friday. Glover has been on the disabled list since April 26 with a left hip impingement. He’s been eligible to get reinstated since Saturday, but the club wanted him to throw off a mound first. Glover said he expects to be ready by the end of the week.

● Left-hander Sammy Solis didn’t travel with the club to Philadelphia and isn’t in Baltimore he recovers from nerve inflammation in his elbow.

“We thought it’d be better if he stayed back and worked with our trainers and instructors to try to get him back with us,” Baker said. “Nerve [damage] takes a lot longer to heal than if he had a muscle [problem] or something. So I haven’t really asked about Sammy because we’ve only been gone like five days. It seems like a month. But we’ll find out about Sammy when we get back.”

● Baker said he hopes Stephen Drew will begin a rehab assignment this weekend. The utility infielder was placed on the disabled list on April 12 because of a right hamstring strain. He began taking infield and hitting last week, and has since added running to his workouts.