WASHINGTON -- After signing right-hander Chien-Ming Wang to a one-year deal, Nationals general manager Mike Rizzo indicated that he wants to add another veteran starter to the rotation.

According to a baseball source, the Nationals have expressed interest in free-agent right-hander Roy Oswalt, who played with the Phillies this past season.

In the spring of 2010, Rizzo had interest in Oswalt when the righty was with the Astros. Rizzo wants a veteran pitcher who could lead a rotation that features young right-handers Stephen Strasburg and Jordan Zimmermann.

"The type of pitcher we are looking for is a good leader-type of guy that throws a lot of innings, has shown that he can win in the big leagues and really lead our staff," Rizzo said without mentioning any names. "It's not by having the best stuff on the staff, but showing how to be a professional, how to be a winner, how to pitch 200 innings in a season many, many times in a career. That's kind of the guy we are looking for."

Oswalt has pitched over 200 innings in a season eight times. This past season, Oswalt, 34, pitched in a career-low 23 games for Philadelphia, going 9-10 with a 3.69 ERA. He missed over a month because of back issues. The Phillies declined Oswalt's option, making him a free agent, and the Nationals feel he is still healthy enough to make an impact to the rotation.

During his 11-year career, Oswalt is 159-93 with a 3.21 ERA. He has won 20 games in a season twice.

Calls to Rizzo were not returned.

In other Nationals news, Washington is looking for a bench coach after Pat Corrales was reassigned to the team's Minor League system.

According to a baseball source, third-base coach Bo Porter and Triple-A Syracuse manager Randy Knorr are long shots to be by manager Davey Johnson's side. The new bench coach most likely will come from the outside and become Johnson's successor.

Johnson and Rizzo were not available for comment.