Glen Johnson replaces Roy Jones Jr.

Former light heavyweight champion Glen Johnson's biggest victory was his ninth-round knockout of Roy Jones Jr. in their 2004 world title fight. Now Johnson is stepping in to replace Jones in another fight.

Jones was in the process of finalizing a fight with cruiserweight Bobby Gunn, but when completing the paperwork dragged on, Jones instead took a different offer for a fight in Russia. Johnson then agreed to step in and will face Gunn in a scheduled 10-round bout on Dec. 18 at the Sands Casino Resort in Bethlehem, Pa.

"He's a natural cruiserweight and has fought some big names. This is my first fight at cruiserweight and there's definitely some risk with doing that, but I'm looking forward to the challenge," Johnson said. "I've been working on some new stuff [in the gym] and I feel energized again. I needed a break from boxing and now I feel like a new fighter. I'm looking forward to the 18th and am excited about getting in the ring to show what I still have."

In recent fights, however, it has not looked like Johnson, who turns 45 on Jan. 2, has much left. He won his last fight on April 19 by second-round knockout in the Dominican Republic against low-level opponent Junior Ramos.

However, Johnson (52-18-2, 36 KOs), of Miami, had lost his previous four bouts, albeit against top opposition, including to Carl Froch and Lucian Bute in super middleweight world title fights.

Gunn (21-5-1, 18 KOs), 40, of Hackensack, N.J., is nowhere near their level. In a 2007 cruiserweight world title fight, Gunn was knocked out in the first round by then-titlist Enzo Maccarinelli.

Gunn has also lost his last two fights, getting stopped in the fourth round of a cruiserweight title fight by Tomasz Adamek in 2009 and in the fifth round by long-faded James Toney in an April 2012 heavyweight fight. During his long absence from the boxing ring, Gunn participated in bare-knuckle fights.

"To be honest with you, this is a way tougher fight," said Gunn, comparing the iron-chinned Johnson to Jones. "It's been a dream of mine to fight Roy Jones Jr. as long as I can remember but he backed out only a few weeks before fight night. I'm very thankful that Glen Johnson accepted the bout on short notice. He's fought everybody you can think of and was on the wrong end of a lot of bad decisions.

"This is a very dangerous fight for me, but I'm a fighter and what fighters do is fight. I know he's never been knocked out before and was only stopped on his feet once [by Bernard Hopkins in a middleweight world title fight in 1997] but he's also never faced a solid cruiserweight. My goal is to end the fight early and take my frustrations [over the Jones situation] out on Johnson."