"Everyone is taking it a bit lightly," Snowden said.
Chasing his sixth win in succession and fifth this campaign, Mazu remained a $2.70 top pick after the declaration of the final field of 15 on Wednesday.
It followed the decision by Queensland racing officials to switch the meeting from Doomben to Eagle Farm over concerns the Group 1 program would be washed out if it remained at its traditional venue.
Snowden has previously compared Mazu favourably with his dual Everest winner Redzel with both horses rising to prominence after being gelded.
And while his faith in the three-year-old's ability remains, Snowden cautions that Mazu has done most of his racing against his own age and must now take on a field of seasoned campaigners including Kementari, Shelby Sixtysix and Count De Rupee.
"If he is going to measure up to what we think he will, he has got to run really well because it is a big test for him," Peter Snowden said.
"It's weight-for-age, he gets hardly anything off the other horses, seasoned horses.
"They are hard, tough, horses and he is only just out of restricted grade really. I know he won a Group Two last start, but it was against his own age.
"I'm not taking it lightly at all. I am very focused on what we're doing with him and I'm confident he can run well."
Regular rider Sam Clipperton has been an important part of Mazu's journey and will make the trip to Brisbane to partner him from barrier eight in the Doomben 10,000.