Age should not be any barrier

physicality and ruggedness. We have young centre-backs in Rob Kiernan and Danny Wilson.

“So another senior centrehalf will be good for us.”

Rangers have had Philippe Senderos training with them and Warburton was hugely impressed with the physical condition of the 31-year-old.

He said: “You are talking about a guy who has been training on his own, not with a team.

“But players are getting more experienced and knowledgeable.

“These guys have personal trainers and know their bodies.

“Philippe went to Inter Milan and said he learnt a lot in that year in terms of training and looking after your body.”

Warburton says it’s hard for Rangers to look beyond England when it comes to recruiting players.

He explained: “We took a midfielder, Jota, from Spain when I was at Brentford. What a tremendous player he is.

“But during the first three months, we had to play him for no more than an hour and sometimes leave him on the bench.

“We had to get him used to the pace and intensity of the Championship.

“He’s now valued at about £8 million and cost £800,000.

“We can’t buy a player for £1 million at Rangers and leave him on the bench for three months. We don’t have that luxury.

“I hope the work we’re doing now puts us in a better position in the future.

“We can get some success and then be more attractive to players from overseas.

“It can be difficult when there’s a variety of agents offering us players – and they’re all world beaters!

“It’s amazing, but that’s the nature of the beast.”