Robert Whittaker is focused on his upcoming bout with Luke Rockhold at UFC 221, but that doesn't stop the UFC middleweight champion from wondering what might have been.

After winning the division's interim crown in July, the hard-hitting New Zealand native waited in the wings to face the winner of Georges St-Pierre and then-champion Michael Bisping in a bout that would unify the belts into one undisputed title. When St-Pierre submitted Bisping to win gold back at UFC 217 in November, a showdown between Whittaker and the pound-for-pound great was all but guaranteed by UFC President Dana White.

Nevertheless, St-Pierre cited medical issues for needing time away from the sport once more, and the promotion wasted no time moving on. Whittaker was deemed the official divisional champion, and his first title defense against Rockhold was set shortly after for Feb. 11 in Perth, Australia.

And while Whittaker is looking forward to mixing it up with the former UFC and Strikeforce titleholder, that doesn't stop him from lamenting the missed opportunity to face a fighter he's admired from afar in GSP.

The reigning middleweight champion stopped by Submission Radio (h/t Dana Becker) and shared his thoughts on not getting the chance to test himself against a legend like St-Pierre.

“I wanted to fight Georges out of respect more than anything," Whittaker said. "I idolized him as a child coming up, and as a young man coming up in my career he was always like one of my biggest idols. To be able to fight him would’ve been great. To put him on my resume and say I fought Georges St-Pierre, that was great, but I don’t think I ever really convinced myself that he would fight me. I think it was a dangerous fight for him, a hard fight for him, and it is what it is.”

With his next opponent now official, Whittaker has shifted his focus away from a chaotic "what if" scenario, and onto the task of defeating a game opponent in Rockhold. The clear-cut path is the one Whittaker prefers and he believes it will allow him to bring his best to the cage at UFC 221.

“What it did do was it gave me direction, it gave me an opponent, it gave me a place, a time, and it gave me something to strive for,” Whittaker said. “I’m very objective-driven, so to be given an opponent and a place and a time and a date, it’s great for me.”