Werth to miss fifth straight game, Bernadina in left (updated)

Jayson Werth is out of the Nationals' lineup for a fifth straight game with a tight right hamstring. Bryce Harper will play right field again in Werth's absence, and Roger Bernadina will man left field this afternoon against the Tigers. Nationals manager Davey Johnson said that an MRI on Werth's hamstring looked good upon first glance, but team medical director Dr. Wiemi Douoguih will give the test results a more careful examination later today. Werth has been put on antibiotics to try and get rid of a stomach bug that he's been battling recently, something the Nationals feel might be the root of the problem with the hamstring at this point. "I imagine what he's on, he'll be good to go soon," Johnson said. "I think if, what I'm hearing, they can get to the cause of it. And I think it's more dehydration that's causing the problems with his legs." Bernadina is just 3-for-29 on the season, but he did notch two hits on Sunday against the Pirates, when he came in to replace Harper, who had been ejected in the first inning. The Nationals will face Doug Fister this afternoon, a 29-year-old right-hander who is 4-0 with a 2.38 ERA this season. Fister has worked at least six innings in each of his last five starts and has not allowed more than three runs in any of his outings this season. Dan Haren goes for the Nats, looking to continue moving his 2013 campaign in the right direction. Haren's coming off an eight-inning gem his last time out, in which he held the Braves to just one earned run and four hits. For the Nats CF Denard Span LF Roger Bernadina RF Bryce Harper 3B Ryan Zimmerman 1B Adam LaRoche SS Ian Desmond 2B Danny Espinosa C Wilson Ramos RHP Dan Haren For the Tigers CF Austin Jackson RF Torii Hunter 3B Miguel Cabrera 1B Prince Fielder LF Andy Dirks SS Jhonny Peralta C Alex Avila 2B Omar Infante RHP Doug Fister Update: Werth took batting practice before today's game and did some sprinting and agility drills in the outfield. He looked to be moving well and without much restriction. There's a chance he's available off the bench today in a pinch-hitting situation, but Johnson usually prefers to take things very carefully with hamstrings and might wait another day before looking to get Werth into a game.