The Lotto Soudal rider pointed to Melbourne's heatwave and the Cadel Evans Great Ocean Road Race on Sunday as the reasons he was not in the thick of the action at Albert Park.
The pancake-flat F1 course at Albert Park would normally be prime territory for the sprint ace, but he did not score any points.
Italian speedster Elia Viviani won the sprint category and his powerful Deceuninck-Quick Step team took out the overall title.
Ewan and his Lotto-Soudal teammates rode up from Geelong before the race as the temperature hit 40 degrees.
His main objective this week is Sunday's Cadel Evans Great Ocean Road race in and around Geelong.
"I'm alright - I was very hot and a bit tired," Ewan said after Race Melbourne.
"I just didn't want to go too deep, because if you go too deep in the heat, sometimes it takes a few days to recover.
"The more important one is on Sunday."
While the steep Challambra climb is a key feature of Sunday's event, Ewan gives himself a chance.
He finished second last year at the Milan-San Remo classic, which also features climbing before the high-speed finish.
"It's a course that can suit me, depending on the way it's raced," Ewan said of Sunday's event.
"It's one of those races where it can be a small bunch sprint or it could be in pieces
"I guess that's what is exciting about it. You never know what's going to happen.
"And is kind of like Milan-San Remo, where you can see (Vincenzo) Nibali and I on the same podium."
Ewan remains dirty about last week's relegation after he crossed the line first in stage five of the Tour Down Under, but adds he is moving on from the controversy.
"It was disappointing, obviously, but I've got bigger races that I want to win this year and there was still a lot of good stuff to take out of it," he said.
"Obviously, in that sprint, I was never intending to endanger anyone.
"Maybe it looked a little bit worse on TV than what it was."
After Sunday, Ewan will train in Australia for several weeks before heading to the late-February UAE Tour.