Ally McCoist believes it will take two or three years before Rangers are ready to challenge Celtic for the Scottish Premiership title.

The former Rangers striker, who managed the Ibrox side from 2011 until 2014, believes fans will need to be patient as Mark Warburton attempts to close the gap on the Scottish champions.

Warburton led the club to promotion last term and head into Saturday's Old Firm derby at Celtic Park one point behind their rivals having played a game more.

Asked how he viewed the team's progress under his successor, McCoist said: "They have been fine. I was never of the opinion that Rangers were going to come in and set the place on fire and win the league by some considerable distance.

"The building process is still quietly in operation. I think it is still going to be two or three years.

"What we are seeing from Rangers at this moment is what I expected it to be.

"There will be games where things don't go their way. Obviously the standard of opposition is better than it has been in the last few years so they are finding their feet.

"There has been some good performances, one or two average performances but all in all, Rangers are okay at the moment.

"I know what Rangers fans and Celtic fans are like. "As fanatical as they are in their support of the team, they are not the most patient and some of them perhaps are not the most realistic.

"Rangers and indeed Celtic have improvement in them, particularly Rangers, if they want to challenge for the title and cups on a regular basis and get back on to the European scene."