WASHINGTON -- The Nationals acquired left-hander Tom Gorzelanny from the Cubs for three Minor Leaguers -- outfielder Michael Burgess, right-hander A.J. Morris and left-hander Graham Hicks -- on Monday, according to two baseball sources.

The Nats have not confirmed the trade, which is pending a physical. None of the three Minor Leaguers is considered among Washington's top-10 prospects.

According to another source, Gorzelanny became expendable after the Cubs acquired right-hander Matt Garza in a trade with the Rays.

Gorzelanny is one of eight pitchers who will compete for a rotation spot. He is coming off a season in which he went 7-9 with a 4.09 ERA in 29 games (23 starts) with Chicago.

The 28-year-old has been in the big leagues for six seasons, going 36-37 with a 4.68 ERA. His best season was with the Pirates in 2007, when he posted a 14-10 record and a 3.88 ERA.

"He is a competitive lefty who is going to add to depth to the rotation," said Washington reliever Sean Burnett, who played with Gorzelanny in Pittsburgh. "He will make our rotation deeper. It was a good acquisition for us."

This past Friday, general manager Mike Rizzo said that he was happy with the stable of starting pitchers he has on the roster. He pointed out that Jason Marquis, Jordan Zimmermann, Ross Detwiler and Chien-Ming Wang will be 100 percent healthy, and John Lannan and Yunesky Maya will be more consistent. Add Livan Hernandez to the mix, and the Nationals could have a strong rotation, according to Rizzo.

"I'm really excited about our rotation," Rizzo said. "I see a much-improved Jordan Zimmermann, who is going to take the next step after having Tommy John surgery. He is going to turn into the pitcher we think he is and 14 other clubs think he is. He is the guy that is in demand every time we try to make a trade.

"Zimmermann won one game last year, Marquis won two, Detwiler won one and Maya won zero. I think there are six guys that are going to be much better than they were last year. The pitching is going to improve, because we have guys who have track records that say they are going to improve.

"Marquis is going to get back to being Jason Marquis. Yunesky Maya is going to be the guy our scouts thought he was when we signed him."

The three Minor League players were long shots to make Washington's big league club. Burgess, the 49th pick in the 2007 First-Year Player Draft, hit a combined .265 with 18 home runs and 85 RBIs for Class A Potomac and Double-A Harrisburg this past season. He was Potomac's representative in the Carolina League All-Star Game in 2010.

Morris, a fourth-round pick in the 2009 First-Year Player Draft, was a starter and reliever this past season, going a combined 5-3 with a 3.77 ERA for the Gulf Coast Nationals and Potomac. He made 12 starts and 11 appearances out of the bullpen, showcasing a fastball in the mid-to-upper 90s with sink.

Hicks, a fourth-round pick in the 2008 Draft, started a combined 16 games for Class A Vermont and Hagerstown, and he went 2-6 with a 5.02 ERA.