"About two weeks ago his coat hadn't come through and he was a bit behind but he has really come on since we brought him south," says Pukekohe-based Mangos.
"This is a very strong trial and I think we are in for a very strong Cup. When you add Copy That and maybe an Aussie or two and then horses like Akuta and some of the others, it is going to be a deep Cup."
Mangos knows that means South Coast Arden will need to return to his red-hot form of last season if he is going to be competitive this spring.
"I think he can but this trial will bring him on a lot and tell us where we stand.
"And then he will race next week and probably in the Methven Cup and Ashburton Flying Stakes." South Coast Arden will start on the unruly off a 20m handicap today and while Mangos expects him to be a touch nervous in his first few standing start outings he will see how his manners progress before he considers taking him off the unruly, something which could be crucial to his Cup chances.
Also trialling tomorrow (Wednesday) will be champion trotter Sundees Son returning off 40m in the main trot trial.