Rigondeaux vs Agbeko undercard: Willie Nelson tears elbow, out of fight with Matthew Macklin

Matthew Macklin vs Willie Nelson, which was set for the December 7 HBO broadcast, is now off after Nelson suffered an elbow tear in camp, according to Dan Rafael's report at ESPN.com. Lou DiBella says that Nelson was sparring Darnell Boone when the injury happened.

"Darnell Boone tied him up and Willie heard a pop in his elbow," DiBella said. "We got verification over the weekend that he has the tear and can't fight Macklin. Willie is probably going to be out for about four months. He probably won't be able to fight until about mid-March."

Nelson (21-1-1, 12 KO) has emerged after a ShoBox upset in November 2011, winning his last five fights, including wins over then-unbeaten prospects Yudel Jhonson and John Jackson. In his last two, he's beaten Luciano Cuello and Michael Medina.

The 6'3" junior middleweight, who was moving up to 160 for the Macklin bout, is trained by Jack Loew, who has frequently encouraged him to use his jab more liberally, say, two or even three times more than his instinct may tell him.

Macklin (29-5, 20 KO) will still fight on the card for now. DiBella tried to make a fight with Max Bursak at HBO's suggestion, but Bursak's team turned down the fight due to the short notice.