The former Ibrox midfielder felt the 'woeful' centre-back should have been hauled off with the likes of Ben Godfrey sitting on the bench awaiting an opportunity.

Ferguson could not believe Fernandez lasted 45 minutes - let alone the full 90 - and feels that opens Derek McInnes up to criticism for not making changes earlier.

And he felt sorry for Olwethu Makhanya - Rangers' best player on the night - as he played alongside Fernandez in defence.

Speaking on BBC Sportsound, the pundit said: “Hearts were brilliant, but for Rangers it’s food for thought for Saturday against Aberdeen because I felt Derek was slow to make changes.

“Look at Fernandez - I can’t believe he played 90 minutes, he was woeful. I would have taken him off in the first half.

“His body language was all over the place, his overall play.

“It doesn’t give the rest of the players confidence round about him.

“Makhanya was Rangers’ best player, he’s got a lot to deal with when he’s got someone to his right-hand side like that who is so poor.

“There’s good players waiting on the bench who should have been given an opportunity a little bit earlier.”

Ferguson was surprised Rangers did not adopt the same aggressive approach that worked so well for them at Celtic Park.

“You look at Rangers coming here and you think when they went to Parkhead how aggressive they were, on the front foot," he added.

“Now you can’t just live on that you’ve won a couple of games against Celtic.

“This is what wins you league titles, when you go to places like Tynecastle.

“And the players would have known what is expected of you when you come here and if you don’t go aggressively, you don’t get up against your opponent, you’re going to come out second best.

“I just thought that Hearts were absolutely tremendous. They were brilliant.

“Braga, Miller, Kerjota and McPake were sensational.

“Mendy and Magnusson in the middle of the park patrolled that area and at the back they were good.”