The Oct. 6 return of Conor McGregor in what is expected to be the biggest fight in UFC history appears to now have a fail-safe backup in case of emergency. 

A tweet late Thursday from former lightweight champion Anthony Pettis (21-7) seemed to confirm that his return at UFC 229 in Las Vegas will come against former interim titleholder Tony Ferguson (25-3). MMAJunkie.com was first to report the fight is signed with a formal announcement from UFC still to come.

The fight could end up serving as the co-main event for the much-anticipated return of McGregor following a two-year hiatus. The brash Irish star is set to challenge current 155-pound champion Khabib Nurmagomedov for the title he was stripped of but never lost, with the grudge match between them increasingly juicy considering McGregor's attack on "The Eagle" just days before Nurmagomedov defeated Al Iaquinta for the vacant title at UFC 223. 

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Not only is Ferguson-Pettis an extremely attractive fight between exciting strikers who both formerly held a piece of the lightweight title, it doubles as a smart insurance policy for UFC should McGregor or Nurmagomedov suffer injury or miss weight. At the same time, it's also a tremendous gamble for the 34-year-old Ferguson, who has seen freak injury and happenstance derail his title hopes on numerous occasions. 

Ferguson lost a chance to fight for the interim title originally at UFC 209 in 2017 when Nurmagomedov withdrew following a difficult weight cut. Although Ferguson defeated Kevin Lee later that year to claim the interim belt while McGregor continued to sit idle, he suffered a serious knee injury in April while doing media ahead of UFC 223, which marked the fourth time a scheduled fight between he and Nurmagomedov failed to come off. 

Both McGregor's full title and Ferguson's interim belt were stripped the moment Nurmagomedov and Iaquinta entered the cage in April. 

Considering he's riding a 10-fight win streak in the sport's deepest and most dangerous division (and isn't getting any younger, to boot), Ferguson is essentially risking everything he has built for a fight that, in theory, wouldn't bring him any closer to a much-deserved title shot than he already is. A recent tweet from "El Cucuy" appeared to cement just how hungry he is to get back into the cage under any circumstance and put this difficult year behind him. 

Pettis, 31, has been on quite an adventure after losing his lightweight title to Rafael dos Anjos in 2015, in the first of a shocking three-fight losing streak. He has rebounded to go 3-2 over his last five bouts, but has traded wins and losses in each one. 

The good news for Pettis, who once adorned the cover of a Wheaties cereal box as one of UFC's hottest rising stars, is that he enters the Ferguson fight fresh off a submission win over Michael Chiesa at UFC 226 in July. The dominant performance showed glimpses of the "Showtime" of old. 

The grudge match between McGregor and Nurmagomedov, along with the fact that their title bout pairs the former champion against his unbeaten replacement, has many believing the card could become the first in MMA history to eclipse two million pay-per-view buys. Only four boxing PPVs have reached that level in history, with each one headlined by retired pound-for-pound king Floyd Mayweather, including his TKO of McGregor last August. 

For the complete and updating UFC 229 card, click here.