Rep. Chris Van Hollen (D-Md.) has agreed to play the role of GOP vice-presidential nominee Paul Ryan in Vice President Biden’s preparations for this fall’s debate between the two, according to two people with knowledge of the move.

Rep. Chris Van Hollen (R-Md.). ( Melina Mara/The Washington Post)

The move raises the national profile of Van Hollen, the ranking Democrat on the House Budget Committee and a rising star in his party. It also gives Biden a sparring partner who possesses perhaps the most intimate knowledge of Ryan and his budget blueprint of any Democratic lawmaker on Capitol Hill.

Van Hollen was a central figure in the 2011 debt-ceiling battle. He worked closely with Biden during last spring’s “Blair House” negotiations on debt reduction, which were led by the vice president, and he was also among the 12 lawmakers who served on the unsuccessful debt “supercommittee” last fall.

The Romney campaign has not yet announced who will play Biden on the GOP side.

The vice-presidential debate is set to take place on Thursday, Oct. 11, at Centre College in Danville, Ky. It will be moderated by ABC News senior foreign affairs correspondent Martha Raddatz.