DECLAN John is confident he will be able to cope with being pitched into the Old Firm game at Ibrox on Saturday if Rangers captain Lee Wallace is ruled out through injury - and he can shake off an ankle knock.

John, the Cardiff City loanee, made his debut for Pedro Caixinha’s side in their Ladbrokes Premiership game against Partick Thistle at Firhill on Friday night when Wallace limped off after 12 minutes with a recurrence of a groin strain.

Auchenhowie medical staff will assess the Scotland internationalist this week to determine if he can play in their Betfred Cup quarter-final against Thistle at Firhill tomorrow evening and the Premiership game with Celtic this weekend.

However, if the defender is unavailable then John, who played for Cardiff in the Barclays Premier League at the beginning of his career, believes that he will have no difficulty deputising for him.

The 22-year-old, though, has revealed he has an ankle problem himself meaning that Caixinha, whose side was beaten by a record 5-1 scoreline the last time they took on their city rivals at home last season, may be without his two first choice left backs.

“I want to play as many minutes as I can,” he said. “I have got a bit of a niggle as well so we will just have to wait and see. But Celtic and Rangers are the two biggest clubs up here and to be able to play in one of those games would be superb for me.

“The only game that I have watched is Rangers and Celtic. I haven’t got much knowledge of the football up here, but I got a bit on Friday night. The biggest game I have played in is Cardiff and Swansea, but obviously the derby here is massive, we all know that. I am looking to hopefully feature in that as well.”

John, who looked dangerous going forward, but was unable to prevent Rangers losing a one goal lead and drawing 2-2 with Thistle on his debut, could find himself in direct opposition to Patrick Roberts if he is passed fit and gets the nod to play against Celtic.

But the prospect of pitting himself against the £12 million Manchester City winger is not one which daunts him.

“I have seen him play before and he did quite well last season,” he said. “When you are playing in the Premier League at 17, 18 years of age, you are coming up against all these good players. It did take some time getting used to, but I have come up against good players in my time. I am not really going to fear anyone that I play against.”