Celtic's visit to Aberdeen on Wednesday is a must-win game for their Scottish title hopes - and more important than Sunday's Scottish Cup quarter-final against Rangers - according to former midfielder Peter Grant.
Grant believes the reigning champions' chances of overhauling leaders Hearts and second-top Rangers "would have been over" had they not come from behind to draw 2-2 in Sunday's Old Firm derby and if they did not have a game in hand.
"Going to Aberdeen, it's never been easy," Grant told the BBC's Scottish Football Podcast despite the hosts' indifferent season. "But it's a must-win for Celtic.
"You've got to win that game in hand because I would rather be sitting in Hearts' position, all the games played, points in the bag, there is absolutely no doubt of that.
"Hearts are in pole position. Celtic-Rangers have to continually win because Hearts are sitting up there now and, if they continue to win, nobody can do anything.
"People will be talking about the Rangers game in the cup next week. Forget about that. It's all about this one against Aberdeen. That's the most important game in the calendar.
"And, to be fair to this group of boys, they've not played well this season, but they keep going. They've shown guts."
Grant thinks "everybody's in that fight at this moment", the top three plus fourth-placed Motherwell, and "it's going to go that close" that something like a VAR decision or red card could decide the destiny of the title.