And the odds are shortening he will back up a week later to take on last year's winner Addeybb, champion mare Verry Elleegant and Cox Plate winner Sir Dragonet in the $4m Group 1 Queen Elizabeth Stakes (2000m) at the same track.
Whilst a "Heavy 9" rating was posted this morning, predicted warm conditions tomorrow should ensure an improvement to soft ground – and that will be music to the leading Newcastle trainer's ears.
"I don't want to see it really heavy, and a soft track would be ideal for Mugatoo," Lees, who has scratched his other Doncaster acceptor Gem Song because of soreness.
"Mugatoo is going into the Doncaster in terrific order. The extra week with the postponement of the autumn carnival has been in our favour.
"I'm very happy with Mugatoo, and consider him to be a great chance."
Lees won the 2016 Queen Elizabeth at Randwick with Lucia Valentina, and says his confidence is even higher going into Saturday's race.
Hugh Bowman again partners the Australian Bloodstock-raced import, whom he rode brilliantly to land the $5m All-Star Mile at Moonee Valley on March 13 at his last start.
Bowman won the 2016 Doncaster on the mighty Winx, but Lees is yet to taste success in the $3m Group 1 feature on the opening day of The Championships.
He has had six runners in the last decade, with $61 roughie Sense Of Occasion his best result; finishing third to It's Somewhat in 2017.
Lees also saddled $4.80 favorite Le Romain (Bowman) that year, but the gelding was unplaced on a heavy track.
"Le Romain went into the Doncaster with good form, having won both the Southern Cross Stakes (1200m) and Canterbury Stakes (1300m) at Randwick before chasing home Winx (Chautauqua was third) in the George Ryder Stakes (1500m) at Rosehill," Lees recalled.
"But he had no luck at all in the Doncaster, then came out a fortnight later and was narrowly beaten in the All Aged Stakes."
Lees feels Mugatoo's inside draw on Saturday will be a bonus. "There will no doubt be plenty of speed and he should be able to hold a good spot and get a clear crack at them in the straight," he said.
Provided the gelding performs up to expectations and pulls up well, there is every chance he will back up in the Queen Elizabeth.
Lees also runs Collide (Group 2 Chairman's Quality, 2600m) and Never Talk (Group 3 PJ Bell Stakes, 1200m) on Saturday, and Jason Collett will ride the pair.
"We went back on Collide in the Manion Cup last time and he was disappointing," he said. "But we will be more positive on him this time from an inside draw.
"I'm sure he is capable of good improvement.
"Never Talk likes Randwick and the wet conditions. She has been up a long time with some breaks in between and can run well."
Collide will go on to the Group 1 Sydney Cup (3200m) on Saturday week provided he runs well in the Chairman's, and stablemate Raheen House (placed last year) is a "possibility" to join him. Mustajeer has concluded his current campaign and will be a Cup absentee.
. Lees has four acceptors – Loveisili (Open Handicap, 2020m), Juventus (Benchmark 78 Handicap, 1200m), Miss Canada (3YO Quality, 1050m) and Kedah (Class 6 Plate, 1350m) – at Doomben on Saturday, but has not committed any of them to a start just yet.
Doomben improved to a "Heavy 9" today, but Lees wants to check the final track rating before making a decision about running them.
. He also has four acceptors at his home track meeting on Saturday, but has held off confirming a start for aptly-named Eighth Immortal, part-owned by his good mate and NRL eighth immortal Andrew Johns, in the Benchmark 68 Handicap (1200m).'
Lees has recently taken over the training of the gelding, but indicated he may not start him because of his awkward draw.
His other Newcastle acceptors are Wild Sheila (Benchmark 64 Handicap, 1865m), Sian (Class 1 Handicap, 1200m) and Loolwah (Benchmark 64 Handicap, 1400m).
Andrew Gibbons will ride Wild Sheila and Sian, and stable apprentice Louise Day partners imported mare Loolwah, who had two unplaced runs for Danny O'Brien in Melbourne last year before being transferred to Newcastle.
"Wild Sheila will appreciate an increase in distance after resuming in a heat of the Provincial Championships at Hawkesbury last month, and will take further improvement off this run," Lees said.
"I have taken blinkers off Sian, who overraced when resuming at Hawkesbury last month. He has since had a nice trial (stablemate and trial winner Grande Rumore made an impressive Australian debut at Canterbury yesterday) and gets his chance from a soft draw.
"Loolwah is coming up nicely, and I have made a few gear changes on her. She can run well also from an inside draw, but is bound to take improvement from her first run for us."