Barring any unforeseen issues, it will be against his former friend and current rival Rashad Evans.
By virtue of his unanimous decision win over Phil Davis on Saturday, Evans (17-1-1) held on to his No. 1 contender status, but after a fairly grueling five-rounder, he'd have only 12 weeks to heal up any injuries he suffered during the fight and prepare for a title bout. In the post-fight press conference, Evans didn't mention any physical issues stemming from the fight, saying that he was looking forward to the long-awaited grudge match and title bout with Jones.
"Yeah I'm ready to fight in April or whenever," he said. "There's a couple of things I need to work on. I look forward to going into camp and working on things, but I'm looking forward to fighting Jon and giving the fans the fight they want to see."
Evans admitted that it was difficult to prepare for Davis with the possibility of fighting Jones lurking in the background.
"This is the monkey on my back I had to get over," he said. "It was hard to get ready for this fight because everybody kept talking about that fight [with Jones]. It was hard to get excited for a fight like this, but Phil Davis definitely brought it, and now that I won, I get the opportunity to fight Jon, and I'm very excited about it."
Atlanta is the site of Evans' star-making win, as he knocked out Chuck Liddell at UFC 88 at the same arena that will host UFC 145.
Jones, who was in Chicago as a member of the FOX broadcast team, was beaming after Evans' win, saying that he was happy to finally face his former teammate in the cage.
"I can't wait to get past this chapter in my career," he said. "I've been calling him my antagonist because of all the hype and drama. So I'm a happy man. I'm looking forward to retaining my title on April 21st in the ATL."
It's not a lock yet though, as Evans will have to pass a post-fight physical and hope to avoid any lengthy medical suspensions.
If Evans can't make the quick turnaround, former Strikeforce light-heavyweight champion Dan Henderson is likely to get the headlining slot opposite Jones.
The 41-year-old Henderson (29-8) is coming off his thrilling unanimous decision win over Mauricio "Shogun" Rua at UFC 139, a scrap that many have called the greatest MMA fight of all time.
Jones originally won the belt at UFC 128, battering Rua en route to a fourth-round TKO. He then successfully defended it twice, beating Quinton "Rampage" Jackson and Lyoto Machida to cap a banner 2011.
UFC 145 takes place on April 21 from Philips Arena.