Third baseman Vinny Castilla was traded by the Washington Nationals to the San Diego Padres for right-hander Brian Lawrence and cash Thursday night. The move paves the way for Ryan Zimmerman, the No. 4 overall pick in June's amateur draft, to start at third for the Nationals next season. General manager Jim Bowden thanked Castilla "for his many contributions during our inaugural season," then added: "This trade, however, clears a path for Ryan Zimmerman, who we believe will be a fixture at the hot corner in Washington for years to come." The Padres have long been looking for help at third. Sean Burroughs struggled so badly he was sent to the minors in July when San Diego acquired Joe Randa in a trade with Cincinnati. Randa filed for free agency after the season. "In the 10 years I've been a general manager, I was tired of Vinny hitting home runs against us, either in Colorado or Washington," San Diego GM Kevin Towers said. "He's always been a Padres nemesis, not only from the offensive standpoint, but from a defensive standpoint. This guy, I think, is one of the best defensive third basemen in the game."