By Chris Barclay

Former undisputed heavyweight champion of the world Lennox Lewis believes fellow Briton Anthony Joshua needs more experience before trying to emulate his achievement.

The IBF title holder, who faces a mandatory challenge for the belt from New Zealand's Joseph Parker in early 2017, if not before, launched his reign with a seventh-round stoppage of American Dominic Breazeale last month.

Although the IBF has set a January 9 deadline for Joshua to fight Parker, the Englishman could opt for a unification bout with either WBA, IBO and WBO champion Tyson Fury or WBC title holder Deontay Wilder.

Lennox Lewis rates Anthony Joshua but warns the IBF heavyweight champion still needs to develop his craft.

Lewis urged the unbeaten 26-year-old to hold off on the unification scenario in order to build a stronger foundation before risking his belt against Fury (25-0) and Wilder (36-0).

Joshua claimed the IBF title when he demolished American Charles Martin in April and then hype has intensified following his first defence against the durable Breazeale.

"He needs to get a bit more experience before he gets in there with the top guys," Lewis told Sky Sports UK.

"I think he's doing a good job, he's doing what needs to be done. The opponents that are put in front of him, he's knocking them out. He's not wasting any time and that's what people want to see."

However, Lewis said Joshua's 17 professional victories - all by KO - had not yet faced a genuine threat..

"We have to remember that he needs to be developed. We can't just put him in there against anybody [in the] top level. He's not far from the top level right now, because when you look at the landscape of heavyweight fighters, there aren't that many people around."

Wilder, meanwhile, retained his title for the fourth time with a TKO victory over Chris Arreola in Birmingham, Alabama, on Saturday.

Lewis felt 30-year-old Wilder was also still developing as a heavyweight.

"We have to remember Deontay Wilder started at 23 so his experience factor isn't a long time. He's learning as well and it really comes down to the teachers to make sure they have longevity."