Conor McGregor was expected to fight Michael Chandler later this year and that still seems to be the plan on paper. However, things are extremely uncertain right now. McGregor is required to have two negative drug tests in a period of at least six months in the USADA testing pool in order to compete again. As things stand, he is still yet to enter and submit a drug test with July approaching.

He could get an exemption from USADA, but then, there's the issue of him actually competing. Will he actually return to action? UFC president Dana White didn't seem so sure as he recently implied with the money the Irishman had, it's hard to really think about returning to compete. And while Chandler still remains confident a fight will happen, it's not down to him in the end — McGregor pulls the strings and with rumors of him supposedly losing interest in fighting the former Bellator champion, there's a possibility he could face someone else.

So, who could he face instead? Here are five alternatives to Michael Chandler that Conor McGregor could fight in his UFC return.

Charles Oliveira

This is the likeliest fight. McGregor and Oliveira have chirped at each other in the past on social media, and most recently, “Do Bronx” — coming off his impressive win over Beneil Dariush at UFC 289 — campaigned to fight the former two-weight champion.

It's something his coach Diego Lima also wants to see prior to any potential rematch with Islam Makhachev.

“Now, would we do another fight before? I don’t know,” Lima said. “Poirier gave up a shot at the belt, fought [Conor] McGregor and then came back for the belt. Why am I saying that? It looks like McGregor isn’t excited about fighting Chandler. And why did he say that? Maybe he liked Charles’ fight and is excited about that? Who knows.

“Maybe we do a fight at 170 with the [lightweight] title shot guaranteed for next year in Brazil? We know it’s a Fight Night this year [Nov. 4 in Sao Paulo], but it might be a numbered card early next year in Brazil. Charles deserves a belt in Brazil. It’s Charles’ dream to fight in Brazil. And I think he deserves that.”

It also definitely makes sense for both — the winner more than likely gets a lightweight title shot with McGregor earning his biggest win in years while Oliveira makes a lucrative payday. Nobody would be complaining whatsoever — other than Chandler, of course.

Dustin Poirier

Given that McGregor has been on the sidelines for over two years because of a broken leg suffered against Dustin Poirier, it would make plenty of sense for them to run things back a fourth time. Of course, there doesn't seem to be much interest from both parties and it's hard to blame either of them given they've prepared and trained for each other twice in the last two years.

However, it would certainly be the most lucrative of all the options for McGregor while giving him a chance to get some closure in their saga. That's considering the fact that as things stand, Poirier is 2-1 up despite the anticlimactic end to their trilogy fight. For now, Poirier takes on Justin Gaethje in the UFC 291 headliner next month which leads to the next potential candidate.

Justin Gaethje

McGregor vs. Gaethje is arguably the most entertaining matchup we could have. They are still yet to fight each other, clearly don't like each other and exclusively like to fight on the feet. What could go wrong?

In Gaethje's case, it makes sense regardless of whether he beats or loses to Poirier at UFC 291 simply for the fact that it's a fresh matchup and McGregor is on a losing streak as well. Chandler is a fun fight for McGregor — Gaethje is an even more fun (but dangerous) one.

Kamaru Usman

One potential wild card could be former UFC welterweight champion Kamaru Usman. Usman is coming off a unanimous decision defeat to Leon Edwards in their trilogy fight and won't be getting a title shot anytime soon. Last month, he also stated he's only interested in a fight that would excite him and went on to name McGregor as a potential opponent. His pitch? If McGregor wants a third belt at 170 pounds, he'll need to beat the No. 1 guy to get a title shot.

They've gone back-and-forth on Twitter in the past as well over a potential fight and now would be the perfect time to get the wheels in motion even with Usman not having a belt anymore.

Khamzat Chimaev

The least likely option may actually be the most intriguing one. Khamzat Chimaev and McGregor have beefed with each other on social media for a while and when it comes to fan interest, it's fair to say most would be interested in seeing “Borz” battle the Irishman.

That said, Chimaev — who hasn't competed since September last year — is not only slated to fight at UFC 293 in October, but is also expected to only fight at middleweight going forward after his weight miss at UFC 279. While McGregor would be game to fight Chimaev at 185 pounds, there are just too many variables and it seems unlikely as a wholoe. But that doesn't mean it's not an option and a very interesting one at that.