Khamzat Chimaev seems on the verge of a title shot at UFC 308. But as UFC's next big thing approaches his big night, he is dangerously close to being one of its great what-if stories. Long held enthusiasm about Chimaev's potential is increasingly undercut by trepidation.

Chimaev's early performances were as flawless as can be. Chimaev crushed two opponents in 10 days and three in two months, absorbing one strike in totality. It was unlike anything fans had seen. After an incredible debut year, Chimaev was primed to be the mixed martial arts breakout star. Then the problems piled on.

Recurring illnesses, injuries and career missteps have cooled his momentum. Many still believe in Chimaev's upside but there's a growing undercurrent of apprehension.

Let's examine why fans and the UFC may be cooling off on Chimaev ahead of his return against former UFC middleweight champion Robert Whittaker on Saturday.

The UFC sought creative solutions during the COVID-19 pandemic. UFC CEO Dana White and company launched Fight Island in Abu Dhabi to host their fights. The promotion hosted four events in a two-week span from the region in an effort to keep things moving, especially for fighters who were unable to travel to the United States at the time.

Chimaev was perhaps the greatest benefactor of this setup. Chimaev made his short-notice UFC debut on July 16, 2020, dominating John Phillips en route to a Round 2 submission. Chimaev fought 10 days later -- breaking the record for the shortest turnaround between fights in UFC's modern era -- and stopped Rhys McKee with strikes in Round 1. A 17-second knockout win over Gerald Meerschaert followed less than two months later.

Chimaev was a big winner of UFC's COVID-19 era. In a cruel twist of fate, the virus also caused Chimaev's woes.

The UFC scheduled Chimaev for his first UFC main event against top-ranked welterweight contender Leon Edwards. The fight was scheduled three times between December 2020 and March 2021, each time being canceled due to Chimaev's complications with COVID-19. The original date was nixed after both men tested positive; however, Chimaev's long-term complications with the illness forced the other cancellations. Chimaev's lung issues became a serious and persisting issue, even sparking a short-lived retirement in March 2021.

Most recently, Chimaev pulled out of a June date with Whittaker due to illness. After exploding on the scene with activity, Saturday's fight will mark just his fifth appearance in the last four years. Chimaev is no longer a reliable hand for the promotion's busy event schedule at a time when UFC light heavyweight champion Alex Pereira is rescuing cards left and right.

"A lot of shit things have happened in my life, being sick and having surgeries," Chimaev told CBS Sports. "That's why I've been fighting not like I did before."

Before UFC 308 was Chimaev's big night, there was UFC 279. Chimaev was scheduled to headline his first pay-per-view against box office draw Nate Diaz in September 2022. The folk hero was fighting out his UFC contract to procure a lucrative boxing bout with Jake Paul. Most saw this as an incredible mismatch with UFC trying to squeeze one last draw out of a faded star. Chimaev was younger, faster, and stronger with a style tailor-made for Diaz's defensive weaknesses.

The power went out on Chimaev's big spotlight when he stepped onto the scales. The Chechnya-born fighter missed weight by a huge margin of 7.5 pounds. Diaz cleverly evoked his contractual right to turn down the fight, forcing UFC to scramble. Multiple fights were shuffled to rescue the card. Diaz had a hero's sendoff by defeating Tony Ferguson in the main event; meanwhile, Chimaev steamrolled Kevin Holland at a catchweight. Sure Chimaev won, but he almost imploded a UFC PPV. Chimaev hasn't been booked for a welterweight fight since.

"I believe we just started too heavy this camp," Chimaev's coach Andreas Michael said on "The MMA Hour" after the fight. "We should have had a little more discipline and held our weight to a reasonable level, to a reasonable weight close to the one he's training at and going into camp.

"[Chimaev] is a magnificent fighter and I love him to death -- but, what I'm saying is, it was absolutely unprofessional from our side not to make weight. Anyone who doesn't make weight is unprofessional, absolutely. I want to [apologize] to Nate's camp for that. We should have both made weight, and there are no excuses."

UFC found themselves scrambling again for Chimaev's next fight, but at no fault of Chimaev. Former UFC welterweight champion Kamaru Usman made his middleweight debut on 10 days' notice after Paulo Costa was forced out of a scheduled fight against Chimaev at UFC 294.

Chimaev dominated in Round 1 but looked weathered in the final two frames. Chimaev barely won a majority decision that raised more questions than answers about his potential.

"Kamaru is one of the best guys I've faced. He's been No. 1 pound for pound," Chimaev told CBS Sports, pushing back against those undermining his win. "People forget who Kamaru Usman was. When I beat him, everyone said he wasn't that good but that guy is crazy good."

White had claimed that Chimaev vs. Usman was a title eliminator, but no title shot materialized for Chimaev. He was subsequently booked in another title eliminator against Whittaker in June. When Whittaker vs. Chimaev was rebooked for UFC 308, the promotion did not mention a title shot. According to White, Sean Strickland will next challenge middleweight champion Dricus du Plessis. It could be a matter of timing, but it also suggests there is some skepticism around the top talent.

Check out the full interview with Khamzat Chimaev below.

Chimaev is in an unusual spot. While he's considered a future title challenger, fans, media and fighters alike are split on what could happen if he gets there.

CBS Sports gauged various current and former UFC champions, plus one middleweight contender, to answer the question: will Khamzat Chimaev ever be a UFC champion?

"I think he's world champion caliber," former UFC middleweight champion Chris Weidman told CBS Sports. "But it depends on his health."

"I'm going to say no just based on his track record of not coming through in these fights," former lightweight champion Frankie Edger said. "Does he have the talent to be champion? 100%. But talent isn't enough."

Former women's strawweight champion Joanna Jedrzejczyk compared Chimaev's case to Tatiana Suarez, another highly-touted contender plagued by health issues. Suarez reportedly pulled out of her fight at UFC 310 with an injury, according to MMA Fighting and MMA Melotto, days before CBS Sports published this story.

"He's very talented like Tatiana Suarez but they get injured very often," Jedrzejczyk said. "I think Tatiana will become UFC strawweight champion and same with Chimaev. He's very talented, a super hard worker and gifted fighter. He can be the champion."

Reigning middleweight champ Du Plessis previously predicted the winner of Whittaker vs. Chiamev would get the title shot over former champion Sean Strickland. But du Plessis was cautious about Chimaev's consistency despite how warmly he perceives UFC to treat Chimaev.

"The winner of Khamzat and Whittaker will get the title shot. That's going to happen," Du Plessis told CBS Sports ahead of his fight against Israel Adesanya in August. "Strickland says he's going to wait until he gets a title shot, he's going to wait quite a while in my opinion.

"If Whittaker beats Khamzat, he's on a three-fight winning streak and 100% getting a title shot. The UFC has been wanting to give Khamzat a title shot since his debut. Maybe if it's a draw, Khamzat will still get the title shot in my opinion. Let's see if he gets to the fight."

Fellow middleweight contender Caio Borralho previously trained with Chiamev, and suggests the popular fighter's training regimen is negatively impacting his career.

"I think he has potential to be a UFC champion for sure," Borralho told CBS Sports. "I train with him and I know how good he is. I think he trains too hard and his body isn't taking it. He needs to manage his training camps and nutrition."

Check out the full interviews with UFC fighters below.

The next few weeks are pivotal for Chimaev. If the highly-touted contender defeats Robert Whittaker on Saturday, he's the most deserving contender after du Plessis and Strickland handle business. Chimaev's remarkable UFC career has been clouded by uncertainty, but the fog might finally clear heading into year number five.