The American, who at 27 is nearly four years younger than Benn, packs a powerful punch. Of his 31 victories, all but two were inside the distance, 20 of them in the first round.
Benn's 32 short-cut successes in 39 wins will also earn him more than £1m for a fight which could attract close to an 11,500 sell-out. The promoter Frank Warren, who is backed by the financial muscle of the American promoter Don King, said: "This is probably the best world title fight I have ever put on. It has all the ingredients of an explosive affair. McClellan is a devastating puncher and will be the riskiest-ever opponent Benn has had in his career." Benn, who is making his seventh defence, has flown to Tenerife to set up his training camp.
On the same bill the former world champion Lloyd Honeyghan, who is now 34, meets the former leading amateur Adrian Dodson in an intriguing light-middleweight contest.