Celtic are currently nine points ahead of Rangers at the summit of the Scottish Premiership, with only 15 games played.
Rangers bid adieu to Van Bronckhorst on Monday and are looking to name his successor before the league resumes on 15th December.
Grant believes that the league is now firmly in Celtic’s hands, especially given the amount of quality at Ange Postecoglou’s disposal.
A possible pivotal moment for the Celts could have been Callum McGregor’s injury-enforced absence, but Grant paid tribute to Aaron Mooy and Matt O’Riley who made sure McGregor was not missed.
Grant further noted that the Gers’ squad are not good enough to register a successful comeback domestically, regardless of who is appointed as Van Bronckhorst’s replacement.
“[The squad are] not [good enough] to come back at Celtic this year, no chance”, Grant said on the Go Radio Football Show.
“The league is over.
“I said it last week, the league is over, because of Celtic’s squad and I know the demands of the manager.
“I thought there was maybe a chance when Callum got injured, but they came through that exceptionally well.
“Mooy, I thought got fitter and became a better player for the group and Matt O’Riley put in some big performances in that position.
“Celtic won’t say it’s over, but I’m telling you [it is] and if I was in the Celtic dressing room I wouldn’t say it either.”
It remains to be seen who Rangers appoint to succeed Van Bronckhorst as they try to reel in Celtic after the World Cup break.