Despite picking up impressive results against Manchester United, Manchester City and Swansea so far this term, a 3-0 defeat to Arsenal last weekend dropped the Bluebirds to 17th in the table, three points above the drop zone.
That leaves them level with Mark Hughes' Potters ahead of Wednesday evening's Britannia Stadium clash, with a trip to Crystal Palace to follow on Saturday.
But when asked whether these two games could end up proving defining moments in Cardiff's season, manager Mackay said: "The gap between the bottom right up to 10th is minute, and I don't see that changing between now and the end of the season.
"I have said before that with two weeks to go last season 10 teams could still have been relegated.
"It's about us picking up points and keeping that belief. It is a long-term view I am taking and the group have got belief they can perform at this level, compete at this level and pick up points.
"The last couple of games we have played top teams in this league, but now we are playing teams who are in and around us.
"We all know that counts for nothing. You saw that with Liverpool going to Hull at the weekend. They are both going to be tough games but we will be competitvie and do our best to bring points home."
Mackay also believes it will take opposite number Hughes some time to fully make his mark on the Potters' squad, as he seeks to tweak the direct gameplan employed by his predecessor Tony Pulis.
Mackay said: "Tony Pulis did a fantastic job at Stoke, that was a club that overachieved for five years there.
"Tony did a great job and they became a sustainable Premier League team having been a Championship team.
"Mark has now come in and it will be about him putting his stamp on it, and that sort of thing invariably takes two or three transfer windows."
Cardiff have won just once away from home this season, with Jordon Mutch's late strike giving them a 2-1 victory at Fulham.
And the midfielder admits Cardiff need to start producing their home form when on the road from Cardiff City Stadium.
"If we do that we can pick up quite a few points," he said.
"We'll stick together and work for each other. We want to do the same things away as we do at home.
"Our aim is to do the business Wednesday and Saturday. We are capable of winning against Stoke and Palace and we'll do all we can to achieve that."