The Rs need a result to be sure of staying up - and can gift Manchester United the title in the process.
"Manchester City haven't been in this position for a long, long time and many of their players haven't won the Premier League title before," Mackie told talkSPORT.
"Pressure can do strange things to people. Fans are expecting a massive day for Manchester City but we're scrapping for our lives and a point would mean the world to us.
"We haven't got great away form but that's got to change at some stage. We feel we can go there and try to spoil the party.
"We've got real experience all around the pitch. People will write us off but we're massively focused on trying to get something there. We're fighting for our lives."