Jayson Werth played three innings at Class A Potomac on Wednesday and still felt some tightness in his strained right hamstring, Nationals Manager Davey Johnson said. He is starting in right field again on Thursday and is expected to play five innings. (UPDATE, 9:20 p.m.: Werth went 2 for 3, both singles, with an RBI and played six innings in right field.) Werth told Johnson that he played at about 60 percent on Wednesday in the rehab game. The original plan was for Werth to play four straight rehab games, upping each outing by the innings until he reached a complete game Sunday. But Johnson said Werth won’t play on Sunday. Even then, however, Johnson said, there was “no possibility” that Werth re-joins the team in Atlanta during their three-game series there from Friday through Sunday. The hamstring has confounded the Nationals, as Werth suffered a set-back when playing a rehab game two weeks ago. “Jayson may, after [Thursday], say, ‘I’m ready,’” Johnson said. “It just depends on how much he puts in today and how he feels. He’s still worried about that little bit of tightness in there.”