Right-hander Tony Armas Jr. is to have arthroscopic surgery on his throwing shoulder Wednesday. Armas, 7-7 with a 4.97 ERA, last pitched Sept. 1, giving up seven runs in four innings against Atlanta, and then was dropped from the rotation. He went 0-2 with a 9.75 ERA in his final three starts. The pitcher appeared in a total of just 21 games the previous two years because of major shoulder surgery in May 2003. "His arm wasn't right a lot of the season. Hopefully he can get this corrected once and for all. It's been three years now," Nationals manager Frank Robinson said Friday.