Ferguson was furious after his side lost 2-0 to Hibernian at Ibrox on Saturday and suggested changes were afoot.

He was as good as his word. Six players were replaced from that showing and the main talking point was the man in between the sticks.

Former England international Butland has been under increasing scrutiny after some high-profile blunders and Ferguson finally swapped his goalkeepers - a decision he called "one of the toughest" he has ever made.

Yet the big call paid off as Kelly, making just his eighth appearance since returning to the club from Motherwell, made a few smart saves before stopping a Alex Berenguer penalty in the second half.

"All the chat before the game was about Liam Kelly and he's done himself so proud," said former Rangers striker Steven Thompson on Sportsound.

"He's a leader. He'll have been feeling massive pressure, but when you get given the chance, you've got to take it and he's done that.

"You can't take him out the team now. That was a heroic performance. Not just the penalty save, his distribution was good, his command of his box was good."

Former Scotland striker Steven Naismith agreed, saying: "Kelly is Rangers' number one now."

The back four in the loss to Hibs achieved an unwanted feat - conceding two or more goals in six successive league fixtures for the first time since 1894.

It is a long-winded way of saying that Rangers have been leaking goals and have often given themselves a mountain to climb.

It looked like that might happen again after Propper's dismissal.

However, Naismith suggested the dismissal ironically might have had a positive effect.

"The shock of the red card early on could have changed the dynamic. There's been a siege mentality, us v them, and that's galvanised Rangers.

"They played a narrow 4-4-1, wanting Athletic to play round them. Man for man, everybody is buying in."

Initially lining up in a back three of Dujon Sterling, Propper and Leon Balogun, Rangers were forced to revert to a back four, but they looked significantly more settled than in recent weeks.

On the right, James Tavernier was tasked with marking Nico Williams and the captain would have been a contender for the man of the match award before Kelly's penalty stop.

"He gets a lot of criticism for his defending, but his defending against Fenerbahce and Bilbao has been exceptional," former team-mate Andy Halliday said.

"He's up against a guy valued at £75m and he's made Nico Williams look like the poorest player on the pitch. James Tavernier never gave him any change."

Losing a player so early meant the hosts were always going to be up against it, but they weathered the storm well with the ultimate team performance.

They made 39 clearances, 20 tackles and kept their discipline - even with nine men on the pitch in the final few minutes following Sterling's injury.

It was the "proper Rangers performance" Ferguson had been hoping for.

"That's the exact reaction I wanted," he said. "That's what I spoke about on Monday and the players showed a performance full of heart, grit and determination."

Nico Raskin and 18-year-old Bailey Rice - making only his second start - were organised in midfield.

Behind them, Balogun and Sterling dealt with the imposing threat of Maroan Sannadi, while on the wings, Ianis Hagi and Vaclav Cerny tracked back to help cover.

Up front, Cyriel Dessers fought to win free-kicks while feeding off scraps.

Kelly, the hero of the hour, was also quick to praise his team-mates.

"I never actually had much to do in the game," he suggested. "Once we went down to 10 men, the guys in front of me were absolutely brilliant.

"I just wanted to help the team, I don't really care about me."

That mentality, one of togetherness, is what we have seen on many European nights at Ibrox. Rangers must dig deep to find it again in Bilbao next week.