(Julio Cortez/AP)

Morse appeared as the designated hitter in the Nationals’ 6-3 loss to the Tigers on Tuesday night, will take extra at-bats in a minor league intrasquad game instead, Manager Davey Johnson said, as will Jayson Werth.

Morse first hurt his lat March 6 while warming up for a game. The strain only hurt him when he threw, not when he ran or swung the bat. He received a cortisone shot Saturday, which Morse said relieved the tightness he felt when he threw. But when Morse threw from further than 90 feet Monday, Johnson said, he felt discomfort. Morse received more treatment on his lat Tuesday.

Both Morse and Johnson have consistently said they are not concerned about the injury. Morse is returning to left field after playing first base for the majority of 2011. The Nationals moved Morse back to left for the final month of the season to prepare for him for this year.

On Monday, in his first at-bat since he was sidelined, Morse ripped a double to the left-center field gap. Tuesday night, Morse went 0 for 3 with two strikeouts.

Johnson confirmed Bryce Harper will play Wednesday. During Tuesday night’s game, he hovered around Johnson in the dugout, which Johnson took to mean he wanted to play. He pointed at the lineup card, which did not list Harper’s name as an available reserve. “I said, ‘Can’t you read?’ ” Johnson said.

Roger Bernadina did not play Tuesday night after he got a tooth pulled. Johnson expects him to play Wednesday.

Werth hit his second home run of the spring, and, like his first, it came on the first pitch of an at-bat. Facing Tigers closer Jose Valverde, Werth smoked the first pitch he saw, a fastball, over the right field fence. Johnson has implored Werth to swing at more first-pitch fastballs, and this spring Werth, perhaps the game’s most patient hitter, has complied.

“I’ve liked where he’s at from Day One,” Johnson said. “He’s awful close. A lot of the guys are really awful close to being where they need to be.”

Johnson said Edwin Jackson’s command problems Tuesday night came when he over-adjusted. He began throwing pitches high, and in the third when he tried to bring them down, they zipped just low of the strike zone. Johnson also said some inconsistent results could be expected from Jackson because of his style.

“You’re talking about power arms,” Johnson said. “Those guys always have a little bit more trouble in the spring. I’m not saying this is a lot of trouble we’re experiencing, because we’re not. But the guys usually in the spring who are most successful use a change-up, stop the ball. Hard throwers, they get hit a lot harder. It’s always been that way.”

Johnson also said he thinks some Jackson’s balls could have been called strikes. “It’s spring training for them, too,” Johnson said.