RANGERS will continue to monitor defenders Bruno Alves and Declan John ahead of Saturday’s Old Firm showdown.

The pair had to be replaced during the second half of the Betfred Cup win over Partick Thistle last night as Pedro Caixinha’s side booked a semi-final berth.

Youngster Ross McCrorie took over from Alves, while Lee Hodson came on for John at left-back on his first start for the Light Blues.

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Goals from Carlos Pena, Daniel Candeias and Eduardo Herrera clinched a hard-fought win as the Gers warmed up for the visit of Celtic with a much-needed victory.

Caixinha said: “When we were controlling the second half I had to take Bruno and Declan off at the same time.

“Both have problems and 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.”

Read more: Ross McCrorie: My Rangers debut was a dream come true against Partick Thistle​

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.

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“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 and 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.

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

“The main concern is to recover. They are difference matches, but of course they are connected.

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

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

“Let’s see what this competition has for us. No matter what happens in the draw we are thinking about getting to Hampden for the final.”