DECLAN JOHN insists he is ready to make his Old Firm debut if called upon by Rangers boss Pedro Caixinha this weekend.

The left-back was handed his Light Blues bow on Friday night after captain Lee Wallace was forced off early in the first half of the draw with Partick Thistle.

Rangers return to the Energy Check at Firhill Stadium tomorrow night for a Betfred Cup quarter-final before they turn their attentions to the visit of Celtic on Saturday.

Read more: Derby double header will shape Rangers' season - and maybe Pedro Caixinha's Ibrox future

And John is eager to experience the Old Firm atmosphere as the countdown continues to derby day at Ibrox.

He said: “Of course, I want to play as many minutes as I can. I have got a bit of a niggle as well so we will just have to wait and see.

“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].

“At the end of the day, they are the two biggest clubs up here and to be able to play in one of those games would be superb for me.

Read more: Rangers need to cut out the mistakes in Partick Thistle rematch, says Fabio Cardoso​

“Yeah, of course [I can shut out the build-up]. At the end of the day, I don’t think it matters what game it is, you are going to take it game by game. Hopefully we can get a good result.”

John burst onto the scene as a teenager as he played in the Premier League for Cardiff and earned international recognition with Wales.

He could come up against Patrick Roberts if he is selected against Celtic and he is confident his past experiences will stand him in good stead.

John said: “I have seen him play before and he did quite well last season. We will just have to wait and see on Saturday.

Read more: Declan John disappointed he couldn't mark Rangers bow with a win​

“At the end of the day, 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.”

The loss of Wallace would be a major blow for boss Caixinha ahead of a hugely significant Old Firm encounter.

But John is thankful for the help he has received from the Light Blues captain since he made the move north of the border last month.

He said: “Since I have come in, I have been here for two weeks now, he has put his arm around me, shown me around the place. He is a good guy.

“He has been here for years and he has done so well in his career. He has been showing me some tips in training, which is always good from a player of that stature. I have been taking it all in.”