By Mike Coppinger

Willie Nelson was forced to withdraw from his schedule HBO date with Matthew Macklin after suffering an elbow injury, but the show must go.

Lamar Russ (14-0, 7KOs) will step in to face Macklin on Dec. 7 in Atlantic City, N.J., Macklin advised BoxingScene.com on Tuesday.

"I'm glad that Russ has come in and stepped up to replace Willie Nelson," Macklin (29-5, 20KOs) told BoxingScene.com. "He's undefeated and will obviously be ambitious, but he'll find out early that he's never been at this level before. I'm looking forward to getting back to winning ways and putting the loss to Gennady Golovkin behind me."

Russ hails from Wilmington, N.C., and is known as "The Boxing Cube." The 26-year-old fought two of his last three fights on promoter Lou DiBella's "Broadway Boxing" shows. Russ is managed by Egis Klimas, who also has top fighters Evgeny Gradovich, Sergey Kovalev and Vasyl Lomanchenko in his stable.

Macklin is coming off a third round knockout to Golovkin on HBO. Previously, he scored a one-round knockout of Joachim Alcine before pushing Sergio Martinez to the limit in a championship bout.

Follow Mike Coppinger on Twitter: @MikeCoppinger