Rangers go into the Old Firm game with Celtic on Wednesday in the middle of a mini crisis.

Apart from the 7-1 victory at Dundee last weekend, the Premier League leaders have been inconsistent in recent weeks.

Dick Advocaat's side have now taken only six points from four games, which is hardly championship form.

And they couldn't break down a Saints side forced to field a third-choice keeper in Stephen Robertson.

With Alan Main recovering from a hernia operation, Allan Ferguson retained his place between the posts.

But Ferguson was stretchered off in the 43rd minute following an aerial collision with team-mate Danny Griffin and Rangers skipper Lorenzo Amoruso.

Ferguson went to ground and immediately signalled for help, clutching his left leg.

Robertson came on for a rare game at this level but played with a good degree of confidence.

Rangers dictated the pace and are now nine points clear of Celtic at the top.

But manager Advocaat will surely be concerned at the number of chances that went begging this afternoon.

There was a timely boost for the club ahead of next week's game with Amoruso returning to the starting line up after recovering from an ankle injury.

Saints almost made the breakthrough after just two minutes when John Paul McBride released John O'Neill. However Stefan Klos raced out of his goal to make a timely block.

Rangers then poured forward in numbers and Ferguson did well to block a shot from Rod Wallace and then Seb Rozental.

Chilean striker Rozental got himself into a good position in the 23rd minute but Griffin launched himself at the shot to rescue Saints.

Saints seemed content to sit back and soak up the pressure but it was a dangerous exercise.

They managed to scramble the ball away in the 33rd minute when Wallace played the ball into Andrei Kanchelskis.

But then came that injury to Ferguson, which gave Robertson an unexpected chance.

He acquitted himself well three minutes after the break to turn away a shot from Wallace.

However Rangers continued to be wasteful with Kanchelskis off target in a good position and Wallace firing over the top when clear in the penalty area.

Kanchelskis then hit the bar in the 54th minute when it seemed easier to score and Robertson again came to Saints rescue in the 64th minute, getting down quickly to block Rozental's effort.

Rangers almost wrapped the game up with 15 minutes to go but a shot from Giovanni van Bronckhorst was cleared off the line by McBride.

Gary Bollan followed suit nine minutes from time to deny Dodds, who had replaced the out of touch Kanchelskis.

Teams

Rangers: Klos, Reyna, Vidmar, Amoruso, Numan, Kanchelskis (Dodds 64), Van Bronckhorst, Tugay (McCann 69), Albertz, Wallace, Rozental.

Subs Not Used: Brown, Nicholson, Ross.

Booked: Amoruso, Van Bronckhorst.

St Johnstone: Ferguson (Robertson 43), Frail (McAnespie 74), Griffin, Weir, Dods, Bollan, O'Halloran, O'Neil, Kane, Connolly (Lowndes 57), McBride.

Subs Not Used: McMahon, Jones.

Booked: Kane, Griffin, Dods, O'Halloran, McBride.

Att: 49,907

Ref: Douglas MacDonald (Scotland).