McGregor was heralded as as rising star when he signed with the Rebels in 2016 after playing Australian schoolboys and captaining NSW.

But after a serious knee injury, the young playmaker failed to break into the top side and was let go in 2018, and snapped up by the Force for their NRC team.

Now aged 23 and finding his feet at No.15 after a shift from five-eighth, McGregor feels like he's playing his best football.

He has started every game for the Force and has been among their best.

"Yes definitely, since coming to Perth, I've been given some opportunities which I'm very grateful for," McGregor said.

"The team dynamic is really good at the moment and everyone's really enjoying the opportunity and the chance to play against the best teams in Australia."

The last time the two teams met in 2017, McGregor was with on the Rebels' bench with the Force, who had a nine-point win, cut soon after from the Super Rugby competition.

While he will line up against his former team, many Melbourne players including captain Dane Haylett-Petty, flanker Richard Hardwick, lock Matt Philip and centre Bill Meakes were part of that Force team.

"There's a lot to play for and it will be good coming up against old mates," McGregor said.

"It's in the back of our minds but this is a really important game for us so we're just focused on us and what we can do to get the win."

The Force are yet to secure a Super Rugby AU victory despite holding leads against the NSW Waratahs and Queensland.

Melbourne notched their first win last round against the Waratahs.

"We've had a few good weeks of preparation and the boys have trained really hard this week and we know exactly what we want to do and how we want to play when we get out there," McGregor said.

"It's the last game of the first round before we go into the bye week so we want to put everything into it."

Australian Associated Press