Mackie has faith in the team to get the better of the European champions at home.
"They've had quite a bit of upheaval themselves in terms of changes to the playing personnel, but there's no doubt that they've added great quality to their ranks.
"The likes of [Eden] Hazard and co. seem to have settled in really quickly, but it's about what we do on Saturday.
"We know we can beat the best here at Loftus Road, as we proved last season, and it's up to us to rediscover that winning mentality on Saturday.
"We can turn over the best this league has to offer on our own patch, so I've got every confidence."