The Washington Nationals have added a veteran presence to an already formidable rotation, agreeing to terms with Dan Haren, according to sources.

Haren's deal is for one year and worth $13 million, Fox Sports reported. The deal is pending a physical, multiple sources say.

Haren, 32, endured a disappointing 2012 with the Los Angeles Angels, going 12-13 with a 4.33 ERA -- the worst of his 10-year career -- in 30 starts. He had his contract bought out by the Angels for $3.5 million in November.

"I think it's a great move, if we can get him," Nationals manager Davey Johnson said Tuesday at the winter meetings in Nashville. "Great athlete, outstanding stuff -- gamer. He fits right in. He can swing the bat. If we get that finalized, he'll be a great addition."

A three-time All-Star, Haren would join a rotation in Washington that includes Stephen Strasburg, Gio Gonzalez, Jordan Zimmermann and Ross Detwiler. That rotation helped carry the Nationals to the NL East title last season.

Johnson said he expects Haren to step in as the leader of Washington's rotation next season.

"I've got some young guys that act like veterans, and they pitched like veterans last year for me," Johnson said. "But adding a veteran like Haren is going to make things even better. I've seen him pitch over the years, and he's an intense competitor. Hopefully we'll get it done."

Haren owns a career record of 119-97 with a 3.66 ERA in 296 games.

Johnson said he's fully familiar with Haren and says he might do even better in the NL.