The Freedman father-and-son training team were disqualified for 28 days last month following the conclusion of an accidental race-day treatment inquiry.
Douglas has stepped in as 'caretaker' trainer and has seen his numbers double, joking 'I was born for this'.
While he oversees the Freedman team of horses, it does not mean his own have been neglected with his Everest winner Giga Kick in work and preparing for a first-up tilt at the Group 1 Moir Stakes (1000m) at Sandown in September.
With Giga Kick taking pride of place in the Douglas stable, the work continues with Mr Waterville with the jumps season drawing to a close.
Douglas, who won the Grand National Hurdle as a jockey, has that race on the agenda for Mr Waterville at Sandown next month with a part of the jumper's program being the Deane Lester Flemington Cup 1849 (2800m) at Flemington on Saturday.
A winner of the Australian Hurdle at Sandown in May, Mr Waterville has been a find over jumps this campaign and Douglas believes the gelding can acquit himself well on the flat on Saturday.
At his most recent flat outing, Mr Waterville finished eighth over 2540m at Flemington on June 20 and when prepared by Chris Waller, who retains a share in the ownership of the gelding, he finished second in the 2800m contest held on Lexus Melbourne Cup Day.
"He'll have a little tick over run on Saturday before he runs in the National," Douglas said.
"The 2800 (metres) at Flemington will suit him. He ran really well there over the 2500 (metres) last time and he's been a good performer over the 2800 at Flemington before.
"He ran second at that distance on Cup Day, so we know the trip will be no problem, and for what we've seen on the flat recently, I'm sure he might be one of the chances, especially with no weight on his back."
