Dynamite, 28, sensationally knocked out AJ, 36, in their IBF title clash last year before losing the belt to Oleksandr Usyk, 38, in their July rematch, and Sims believes Dubois must step straight back into elite-level competition.
Speaking to Sky Sports, Sims said: “That’s what he’ll be looking at, getting back into a big fight. He can’t really fight the likes of Usyk and go in to fight a nobody the next fight.”
“He’ll be looking to go straight back in there. But he’s only a young man still … He’s exciting and he can punch, he can box. It’s good to work with him.”
Dubois linked up with Sims a few months ago to assess whether the partnership would work, and the trainer says they have “gelled” well while waiting for a confirmed fight date in early 2026.
Sims insists the heavyweight has been performing strongly in camp and remains confident his fighter is on track for another marquee bout.
Asked directly about the prospect of Dubois facing Joshua again, Sims said: “It’s a possibility.”
Joshua - who faces Jake Paul, 28, in an exhibition fight on December, 19 in Miami, Florida - has only ever lost to Usyk and Andy Ruiz Jr., 36, in addition to Dubois, and fought rematches with both.
Sims, who worked with Joshua early in his professional career, made clear he expects no problems for the former unified champion against Paul.
He said: “If it goes past one round then there’s something wrong with the fight.
“I just don’t see Jake Paul going a round with Anthony Joshua. If it does go past the first round, it doesn’t look good for Anthony.”
Joshua-Paul is widely viewed within boxing as a financially driven spectacle rather than a competitive contest.
The Problem Child has only 13 professional bouts and has never boxed at anything close to heavyweight world-level.
Sims acknowledged the unusual nature of the matchup but highlighted the commercial upside.
He said: “It’s strange, it’s all for the money and it’s all about financial reasons.
“The only upside is it brings a wider scope of audience to boxing … Boxing is flourishing at the minute, especially financially for the fighters.
“These fighters do all this for the money, it is their job. I know Anthony’s already got a lot of money… But if you can give him another bit of wealth he’s always going to take it.
“That's why they do it. They know the career and the life in boxing doesn't go on forever. If it's a one round destruction job, why wouldn't you take it? I don't know anyone who wouldn't take that fight.”
