Former IBF heavyweight champion 'Prince' Charles Martin is going to keep a close eye on the upcoming fight between Anthony Joshua and Kubrat Pulev.

Joshua is scheduled to defend his IBF, IBO, WBA, WBO heavyweight titles against Pulev on a target date of December 12.

The fight was initially scheduled for June 20, but it was pushed back due to the coronavirus pandemic.

Pulev is the IBF's mandatory challenger, while Martin is ranked in the number two spot.

Martin lost his IBF crown when he was stopped by Joshua in two rounds in 2016.

Since then the boxer has rebuilt his career and is now looking for another world title shot.

If for whatever reason the Joshua vs. Pulev showdown falls apart, Martin is ready and willing to step in there to fight either man for the IBF strap.

"Charles is going to fight by the year's end in a 'stay busy' bout, while we wait to see if Joshua vs Pulev actually goes off in December," his manager Mike Borao told Sky Sports.

"In the event Joshua vs Pulev doesn't take place for any reason, Charles will be fit and ready to step in with either fighter and/or fight for a vacated title. Charles is the dark horse of the division. People in the UK may count him out, but given the opportunity, he will prove them wrong and become two-time heavyweight champion!"

Martin feels very confident that he's capable of getting revenge against Joshua.

"Praise him all you want but as soon as he left his comfort zone? He got messed up. He can't weather a storm. He just drops. He hasn't proved himself. He wanted to get all the American fans, be the next Mike Tyson, but it didn't happen," Martin said.

"I ain't taking nothin' from him but, since you asked, I'll tell you - I think he's scared. He's scared. He's scared to get hit. He don't like it. He ain't comfortable with it. When somebody punches back, he ain't comfortable. If you believed that Joshua could [recover], then you should believe that I can. We're in the same boat."