The Washington Nationals placed right-hander John Patterson on the 15-day disabled list with a strained forearm, a significant blow to their already-makeshift pitching staff. Patterson, who has been dealing with the injury for nearly a month now and has not pitched since April 21, was put on the DL retroactive to April 22, making him eligible to return as soon as next week. The Nationals, though, already have mapped out a rehabilitation schedule for Patterson, one that won't have him back pitching in the major leagues until May 13. The club plans to have him pitch in an extended spring training game in Florida on Wednesday, then at Class A Potomac on May 8. Though Washington could "desperately use Patterson in its rotation, general manager Jim Bowden said it was more important to get the injury completely healed. "Our responsibility is to take care of him for the long-term, not just today, tomorrow or the next day," Bowden said. "We need him for the long run, the next three, four, five years."