Anthony Joshua has big plans for 2018 now that he is the biggest draw in heavyweight boxing.

A unification fight against Deontay Wilder or Joseph Parker. A first fight in the United States, or maybe Africa or the Middle East. Even an all-British super-fight against Tyson Fury, if the former champion regains his license.

Before that, though, Joshua must deal with more routine matters: a mandatory defense of his WBA and IBF belts against an opponent few outside the boxing fraternity will have heard of.

Saturday's fight in Cardiff against Carlos Takam — a late replacement for the injured Kubrat Pulev — is hardly getting the pulse racing. Joshua's status is in a new stratosphere after his dramatic victory over Wladimir Klitschko in April in one of the best heavyweight contests this century, so fighting a French journeyman like Takam is something of an anticlimax.

No wonder much of the build-up has been about who Joshua will be fighting next.

"The plan is for AJ to unify the belts in 2018," said Eddie Hearn, Joshua's promoter, "and we really would like to create three massive fights next year."

Losing to Takam would obviously derail all the best-laid plans, but it is highly unlikely. The unbeaten Joshua is disciplined and professional, and says he isn't getting carried away by his elevation to the top of the division. He has also only been taken beyond the third round in three of 19 professional fights, including to the 11th round by Klitschko at Wembley Stadium.

Still — and maybe it is for PR reasons, given that 70,000 people are expected to watch the fight at the Principality Stadium — Joshua is trying not to look beyond the 36-year-old Takam and has been building him up as an awkward opponent.

"People have said, 'Josh, what round? What round?'" Joshua said. "I think we're going for a 10-to-12-round fight because this guy's head is like a block of cement."

Joshua has had only two weeks to adapt to a change of opponent, following Pulev's withdrawal because of a shoulder injury. Takam, who has been stopped only once in 39 fights and has 35 wins, gets in closer to his opponents than Pulev and does more work on the body.

"I need to work on my inside game and stand in a phone box," said Joshua, who described Takam as "durable."

"He disheartens you. Imagine throwing your best shots and they are still in front of you. It's disheartening. To do that for 12 rounds takes a lot of energy so sometimes I'll have to stand in front of him, trade with him, and go to war."

Takam had been on standby since the Joshua-Pulev fight was announced in early September. Still, it came as a shock to Takam when a friend from New Zealand texted him to say Pulev was injured and he'd be replacing him.

"I don't know whether I'm excited, stressed, confused, but I'm definitely ready for the fight," he said. "It will be a proper fight."

The rugby-mad nation of Wales has hosted big boxing bouts in the past, including a fight for the WBC heavyweight title between Lennox Lewis and Frank Bruno in 1993. In front of 20,000 fans at Cardiff Arms Park, Lewis stopped Bruno in the seventh round.

"Prince" Naseem Hamed beat Steve Robinson in a world featherweight title fight at the same venue in 1995, while in 2007, the Principality Stadium — then called the Millennium Stadium — staged Joe Calzaghe's points win over Mikkel Kessler in a high-profile super-middleweight fight.

That was in front of 50,000 spectators, so the Joshua-Takam fight will be the most-watched yet in Wales, another signal of Joshua's popularity.

It is for that reason that Hearn says Joshua will only do stadium fights on British soil, so this is another chance for the champion to get used to the big occasion before potential showdowns against Wilder or Parker.

Wilder, the WBC champion, appears to be the biggest pull for Joshua.

"I think it could be built to be something just like the Klitschko fight. It should be better," Joshua said. "I'm fine staying in the U.K., but America's definitely at the top of the pyramid. Before I wanted to go out there for the experience. Now I want to go out there and make me some money."