Alves and John in Old Firm crock race

that is the reason I was forced to make the substitutions.

“We know we have four days so we need to assess them over the next 24 to 48 hours and see whether we have a clearer idea if they can make it.

“I need to know before I can make my decision for Saturday.”

Boss Caixinha will already be without the services of captain Wallace for the Old Firm clash and the loss of Alves and John would be another blow for the Light Blues.

But the Portuguese has full confidence in 19-year-old McCrorie if he has to step in to the centre of the Gers defence at Ibrox.

He said: “Ross McCrorie is going to be one of the best centre-halves in history, not just for this club but for this country.

“You just need to see what he did. He was brilliant.

“It’s not about age or names. It’s about getting the chance to prove it.

“I have no concerns about him. I never had and never will have. If he needs to play on Saturday, he will play.

“If Declan is unavailable then we have Lee as an option as well.”

After dropping two crucial Premiership points against the Jags on Friday night, Rangers had to endure an extra half an hour at Firhill after Kris Doolan scored a late equaliser for Alan Archibald’s side.

Now Caixinha will turn his attentions to the visit of Celtic as the Gers look to get back on track in the top flight.

He said: “I play one game at a time. I know what I want to do on Saturday. Th The boys will have a day off an and then we will prepare.

“The main concern is to re recover. They are different ma matches, but of course they ar are connected.

“If we were eliminated th then of course the co confidence would have be been knocked down.

“So it’s important to win, es especially a knockout ma match.

“Let’s see what this co competition has for us.

“No matter what happens in the draw we are thinking ab about getting to Hampden fo for the final.”