The Edinburgh club -- a point clear of Celtic at the summit -- need four points from their last two games to guarantee one of the most stunning triumphs in Scottish football history.
Victory over Falkirk at Tynecastle would be enough to seal the title on Wednesday if fourth-placed Motherwell beat Martin O'Neill's Celtic.
Otherwise, the title will be decided in Glasgow on Saturday.
Hearts have not won the league since 1960 and no team other than Rangers and Celtic have won the Scottish title since 1985, when Aberdeen triumphed under Alex Ferguson.
"I've just assumed Celtic are going to win the game (against Motherwell), I've had it in my head that we're going to the last game and I'm prepared for that," McInnes said on Tuesday.
"Listen, there's no easy games for anybody, nothing's straightforward. Motherwell are a more than capable team. They were fully committed against us and I'm sure that'll be the same again against Celtic."
McInnes said the team meeting ahead of Wednesday's match would focus just on the Falkirk game and he would ignore distracting talk of the title.
"I have believed for a while that we've got a team capable of winning the league, just that unshakeable belief in what we're doing," he said.
"We have been trying to hold off a couple of heavyweights for a long time now. We've managed to see off Rangers and we've got to try and see off Celtic over the next two games.
"I think the facts show we're coping brilliantly. We've already broken a club record in terms of points tally and we've got a Champions League qualifier already secured, but obviously we want to try and go one better now and win the league."
Reigning champions Celtic, who have won 13 of the past 14 Scottish titles, were five points adrift of Hearts following a 2-0 loss away to Dundee United in March.
But they have now won six games in a row in all competitions -- including a 3-1 Glasgow derby defeat of Rangers at the weekend.
O'Neill, in charge at Celtic from 2000 to 2005, is in his second spell as the club's manager this season.
He returned for the remainder of the campaign in January, following the dismissal of Wilfried Nancy after an earlier interim stint.
"Celtic Park on Sunday was just kind of reminiscent of my old days anyway and that's been great," said O'Neill, 74.
"But we've gone away from home and we've won some big matches as well too, so just a combination of all of those things gives us a chance."