The highly coveted UFC 300 will take place on Saturday, April 13, at the T-Mobile Arena in Las Vegas. While a headliner for the event is yet to be confirmed, Ariel Helwani reckons Dana White and Co. are working on a special non-main event for the pay-per-view.On the MMA Hour, the veteran journalist said that there seem to be few fights that fit the bill as the headliner for the much-awaited fight card. However, talking about the surprise non-headliner bout, he said:"They have a rabbit in their hat that they're working on. It’s not a main event. There is one, but it's not a main event. Meaning: they’re trying to make this as special as can be, I know that... There are some rabbits. I know there’s one in particular that they’re hoping, I don’t know if it’s going to come to fruition just yet."Furthermore, the 41-year-old speculated that superstars, including Israel Adesanya and Jorge Masvidal, won't be fighting on the card:"I don’t see the big fight out there. I asked around about Izzy, I don’t think he’ll be on there. There’s some talk about Izzy vs. Pereira, I don’t think that’ll happen. Maybe that changes."There’s some talk about Masvidal; he came out and said, 'Unretired.' Masvidal’s not on that card. He’s not referring to [UFC] 300, in case you’re wondering."Catch Ariel Helwani's comments about UFC 300 below (10:50)Per the MMA reporter, Conor McGregor's grand return to the octagon against Michael Chandler would have been the only bout that could've matched the grandeur of the historic pay-per-view as its headliner.Ariel Helwani says Conor McGregor wanted UFC 300Conor McGregor will make his long-awaited return to the octagon on June 29 during International Fight Week against Michael Chandler. However, it seems that it was not the Irishman's original plan.In a recent tweet, Ariel Helwani speculated that 'The Notorious' wanted to make his return at the historic UFC 300 pay-per-view. Last year, 'The Notorious' had also teased the same in a social media post. Helwani's post read:"McGregor wanted to fight at 300. He pushed hard for it. He was ready, I’m told."Conor McGregor has been on a hiatus from the sport since suffering a leg injury during his trilogy fight against Dustin Poirier at UFC 264 in 2021. Per the former two-division champion's New Year announcement, his comeback fight against 'Iron' will happen at 185 pounds.Both men are 2-3 in their last five, with McGregor's last win coming against Donald Cerrone at UFC 246, while Chandler's came against Tony Ferguson at UFC 274 in 2022.