Wilkerson opened the 2005 season as the regular center fielder and leadoff hitter after the Expos moved to Washington and became the Nationals. On December 7, 2005, Wilkerson was traded to the Texas Rangers along with outfielder Terrmel Sledge and minor league pitching prospect Armando Galarraga for second baseman Alfonso Soriano. He hit for the cycle for the second time on April 6, 2005, against Philadelphia (with the Nationals, in their second game after moving from Montreal). Wilkerson also hit the first grand slam home run hit by a Washington Nationals player.