The 20-year-old put in a heavy challenge on Zac Sapsford with the Glasgow giants trailing 2-1 at Celtic Park

The call by VAR to not intervene after Colby Donovan's heavy challenge against Dundee United has been branded "inexplicable" by two former referees.

The 20-year-old put in a heavy challenge on Zac Sapsford with the Glasgow giants trailing 2-1 at Celtic Park, with referee Steven McLean issuing a yellow card for the tackle by the right-back.

Chris Graham and the VAR team would check the flashpoint, but the off-field team would ultimately back up the man in the middle over the booking.

Liam Scales would go on to level the game for Celtic and help keep the Hoops four points clear at the top of the Scottish Premiership - but comparisons would be drawn to the red card issued to St Johnstone's Kai Fotheringham against Rangers last weekend.

The Saints wide man was pulled up by the VAR team at Ibrox for a similar challenge on Nico Raskin at Ibrox - which saw referee Chris Graham sent to the monitor, and a red card issued.

Speaking to BBC Sportscene, former Celtic midfielder Scott Allan noted the similarities between the two incidents: "For me, it's very similar to Kai Fotheringham's for St Johnstone at the weekend, albeit I don't think he makes the same amount of contact.

"I think he does nick the calf, and I think a lot of Dundee United fans will be asking for a bit of consistency. But I don't think he catches him with the same amount of momentum."

Former Rangers man Steven Thompson added: "I suppose all the principles of the challenge are exactly the same, though, and if VAR intervened on Saturday why didn't it intervene it intervene there? I think that's a question a lot of people, certainly Kai Fotheringham, will be asking."

Allan rounded off: "I am looking at it, and it's probably because of the boot. Kai Fotheringham's full boot was on the leg, and I think Colby Donovan just gets away with one there."

Former referees Steve Conroy and Des Roache flagged another challenge - that saw a red card overturned.

Kilmarnock's George Stanger was shown a straight red card by referee Calum Scott against Motherwell earlier this month before VAR checked the incident. The decision was overturned, with the card downgraded to yellow.

The SFA coaching of officials was questioned by the duo. Posting on The Ref's View podcast X account, they said: "Over the past weeks we’ve seen very similar tackles made by Stanger, Fotheringham and Donovan with 3 different outcomes (six, including VAR).

"We seem unable to punish bad fouls when it happens. Bad enough the refs miss it but inexplicable that VAR does with repeated viewings. What’s being coached?"

But former Premier League ref chief Keith Hackett offered support for the match officials, telling Football Insider: "The referee judged this challenge as reckless, hence the yellow card. During the challenge, the offender's body was always in contact with the ground.

"It is that fact and reason why the player got a yellow and not a red card, albeit his leading leg going into the challenge was high.

"It's a yellow card, close to a red, but one that falls just short. I'll support the referee on this one."