"I think the most likely opponent is going to end up being [Liddell]," Sonnen said. "We'll see what happens there, but that's what I think is going to happen."
Liddell hasn't fought professionally since losing to Rich Franklin at UFC 115 in June 2010, which was his third straight defeat and fifth loss in six fights.
John Hackleman, Liddell's trainer, said in May the 47-year-old could potentially return to MMA for the right matchup.
"It would all depend upon—this sounds so bad—seriously, the people who know me know what a terrible mother hen I am when it comes to matching my fighters, but it would depend on the match," Hackleman said on the Anik and Florian podcast (h/t MMA Fighting's Jed Meshew). "I'm not gonna name who I would let him fight—well, it's not up to me to let him fight or not—but who I would OK and who I wouldn't."
Liddell had gotten fans excited when he posted a photo on Instagram showing off his still-impressive physique:
However, Liddell told Bleacher Report's Jonathan Snowden that he had been training for a television commercial instead of an MMA return. He also brushed aside Hackleman's comments, neither confirming nor denying he'd come back to fight.
Bellator would make sense for Liddell should return to the cage. In addition to Sonnen, other aging fighters including Ken Shamrock, Quinton Jackson and Tito Ortiz have capitalized on their star power to earn healthy paydays with the company.
Regardless of whom he's fighting, Liddell's return would almost certainly be a highly anticipated fight among MMA fans.