WASHINGTON -- The Nationals are sending scouts to watch D-backs right-hander Brandon Webb pitch in instructional league games on Saturday and Thursday, according to a baseball source.

Webb will pitch the first game in Tucson, Ariz., while the second game takes place at Chase Field, the home of the D-backs.

Webb, who is a free agent after the season, hasn't pitched in a game in nearly two seasons because of shoulder problems.

It was learned by MLB.com on Friday that he would have interest in playing for the Nationals if he doesn't re-sign with the D-backs. It's not a secret that Webb has a close relationship with general manager Mike Rizzo, who drafted Webb in the 2000 First-Year Player Draft when Rizzo was director of scouting with Arizona.

According to published reports, Webb threw one inning on Wednesday and didn't have any problems throwing the baseball. He told MLB.com that day that his fastball was clocked in the 80s, but he expects the velocity to improve with each outing.

It was the first time Webb faced hitters in a game since Opening Day 2009, when he experienced shoulder discomfort that would lead to shoulder surgery in August of that year.

If he signs with any team, Webb most likely would have to sign an incentive-laden deal given his long period of inactivity.

Rizzo was not available for comment.

Webb may be a risk worth taking. There was a three-year period where Webb was arguably the best pitcher in baseball. In 2006, he won the National League Cy Young Award by going 16-8 with a 3.10 ERA. Two years later, he won 22 games and had a 3.30 ERA with the D-backs.

Maxwell gets rare opportunity against Mets

WASHINGTON -- Nationals manager Jim Riggleman inserted outfielder Justin Maxwell in the lineup Friday because Mets left-hander Pat Misch was on the mound.

The right-handed-hitting Maxwell, 26, entered the game hitting .146 with three home runs and 11 RBIs in 64 games this season.

Next Spring Training may be his last chance to prove that he belongs with the Nationals, because Michael Burgess and Destin Hood are close to being big league ready.

"Justin is such a good athlete," Riggleman said. "He had done fine defensively, he runs the bases very well. He is probably as good a basestealer as there is in baseball. He just didn't get on enough [this season] to display it that much.

"When he hits the ball, he has makes powerful contact. ... He has drawn some walks. He and [hitting coach] Rick [Eckstein] are trying to figure out a way to make more contact. If that happens, you have one heck of player there. If he doesn't, he is getting to the point where time is running out on him. But he is so talented. ... We have been patient with him, we will continue to be patient with him. Hopefully it will all come together, [he will have] a good spring for us and be part of the ballclub for us next year."