Haiden Deegan will not wait until the 2026 Pro Motocross season to make his professional debut on a 450 bike as he announced he will ride in the top division of the World Supercross Championship (WSC) in Argentina and Australia. The announcement was made on the Deegan's YouTube page.

Deegan is seen practicing his 450 on a Supercross track in the video and between the sessions, Deegan said: "It is nice to be back riding and it is a lot nicer because instead of riding a 250, I get to ride a 450. I'm not just coming back to ride the same thing I've been riding, we're on something new. It's like your starting fresh. It's like another step in your career, so it's exciting. I'm going to have some fun and get ready for ... Argentina."

Deegan's mechanic, Brent Duffe, asked Deegan is he was breaking the news in this manner, to which Deegan replied that he thought it was already broken.

"I've been seeing reports that Haiden is racing a 250 in Argentina, but if that's the case, I should probably hurry up and build it," said Deegan's mechanic, Duffe confirmed. "This is the only bike I've built for World Supercross -- Argentina, Australia -- we're coming out in the big boy class."