The list of Nationals to hit the disabled list is growing. Stephen Strasburg will be placed on the DL with a strained lat muscle, Nats manager Davey Johnson said today. Strasburg had originally been scheduled to throw a bullpen session today, but those plans were scrapped. Strasburg merely played catch, but he didn't feel completely right, so the Nats will shut him down for now and place him on the DL retroactive to June 1. "He was examined by a doctor and there's still some tenderness and discomfort there, so we're going to keep him off the mound for a few more days," Johnson said. Strasburg would be eligible to come off the DL on June 16, but there's no certainty that he'll be ready by then. The Nats will continue to play things carefully with their ace, with there being some concern that if he comes back too soon and is still pitching with the lat strain, his arm could be prone to injury. "Until he's symptom-free, we're not going to let him pitch," general manager Mike Rizzo said. Strasburg last pitched on May 31, but was pulled after two innings when he complained of discomfort in his side. The right-hander had been pitching through the discomfort for a couple starts, but it worsened as he went deeper into that start in Atlanta, and he was pulled from the game. Lat strains generally require multiple weeks of recovery time, but the Nationals held off on putting Strasburg on the DL until now, hoping he'd recover quickly and be able to return to the rotation this Saturday. "We were gonna be cautious with him, but all along, we felt that this type of injury is usually a DL type of injury," Rizzo said. "But because he felt good, we wanted to see where he was at."

The Nats have not yet announced who will be called up to take Strasburg's spot on the 25-man roster. They could call up a reliever for the next few days until a starter is needed to take Strasburg's turn in the rotation Saturday, Johnson said. Johnson also said that Saturday's starter will come from Triple-A Syracuse. The two likely options appear to be veteran right-hander Ross Ohlendorf and left-hander Danny Rosenbaum. Chris Young is still on the DL at Syracuse with a lower back injury. The Nats only have 39 guys on their 40-man roster, so they would be able to add either Ohlendorf or Rosenbaum from Syracuse without needing to clear any space on the 40-man. Update: Ohlendorf will likely be added to the Nats' roster and be the guy that will get the start on Saturday. The 30-year-old right-hander was scheduled to start yesterday for Syracuse but was skipped. Ohlendorf has a 4.32 ERA in 12 games this season, but over his last two outings, he's allowed just one earned run, struck out 22 and walked seven over 12 1/3 innings. FOXsports.com reports that Ohlendorf will be activated. The Nats are not saying much on the topic for now, but it appears Ohlendorf is the guy. Ross Detwiler is not a candidate to take Strasburg's turn in the rotation, but the left-hander is coming along well from a back strain that has landed him on the DL. Detwiler threw a bullpen session today in front of Rizzo, Johnson and pitching coach Steve McCatty and according to Johnson, Detwiler "threw the heck out of the ball." The Nats will check with Detwiler tomorrow to make sure he responds from today's mound session well, and if he does, he'll head out on a minor league rehab assignment sometime from Saturday to Monday. "The last time he threw a bullpen, the next day he was stiff," Johnson said. "So tomorrow we'll have to check him and make sure he's not having any discomfort on his side. (The rehab start) could be as early as three days, it could be longer." Detwiler would throw 40-50 pitches in that rehab start and then, barring any setbacks, would likely be able to rejoin the Nats' rotation.