JOHN COLLINS has given new Rangers boss Mark Warburton a stark warning that he has a huge job on his hands at Ibrox.

But the Celtic assistant manager would welcome his own club's old rivals back into the Premiership if the Englishman can handle the step up from Brentford and win promotion at the first time of asking.

Collins said: "It's an interesting appointment. I am disappointed for Stuart McCall, however. I played with him at Scotland, he's a great lad and he went in (to Rangers) at a tough time to try and get them up.

"Mark Warburton did really well by all accounts at Brentford over the last couple of years with results, but it's a big step up to Rangers, a big move for him, The expectation from Brentford to Rangers is miles apart. You are expected to win every game at Rangers.

"He has a big rebuilding job because they have released lots of players and he needs to sign players.

"But Scottish football needs Rangers up, and they need my old club Hibs."

Collins believes his former Scotland team-mate David Weir will be a vital ally for the new man who, at 52, has less than two years as a manager behind him.

Weir, a former Rangers captain, will act as the No.2 just as he did at English Championship outfit Brentford.

Collins said: "David played for a number of years at Rangers. He will be a great assistant because he knows that club inside and out."

Ronny Deila's right-hand man also revealed that the club realise there is pressure on them to add to the squad over the next few weeks.

Collins said: "Every manager and team is trying to get a couple in at this time of the year, it's never easy, and hopefully we can before the Champions League qualifiers.

"These important games come thick and fast for us at the start of the season. We’re back next week, June 23, and it’s an early start because we’ve got the qualifiers on July 15/16."

And when asked about whether Virgil van Dijk would be one to leave, freeing up space for new arrivals, Collins was adamant that wasn't a foregone conclusion.

He said: "Virgil is a class act. A top player. He could play in any team in Europe. There won't be many better centre-halves – what a football player.

"I don't want to talk him up too much because I want to keep him. I train with him every day, and while I played with a lot of talent, he is a great player. Hopefully we can keep him."