Rangers will have to wait until next week before discovering the full extent of Joe Garner's shoulder injury.

The striker had to be stretchered off 15 minutes into the Ibrox outfit's 2-1 derby defeat by Celtic on Saturday after suffering a painful dislocation.

He was rushed straight to hospital for treatment as his team-mates were left to battle Brendan Rodgers' rampant Hoops without him.

However, reports on Tuesday morning claimed the former Preston player had been definitely ruled out for at least four weeks - with a three-month absence also possible if doctors decide he needs surgery.

But Press Association Sport understands Gers boss Mark Warburton is still waiting to hear from his medical team just how bad the £1.8million signing's injury is.

With the joint still badly inflamed, it will be next week before Garner will be able to undergo the scans required to properly asses the damage.

But Warburton will be praying his most costly purchase does not require a lengthy stint on the sidelines.

He has already lost both of his marquee summer signings, with Joey Barton axed and Niko Kranjcar out for the campaign after rupturing knee ligaments, and Aberdeen can reclaim the initiative in the race for the Ladbrokes Premiership's runners-up spot if they win their game in hand.

Garner has netted just three times in 19 outings for the Glasgow giants but his combative style has been the spark for Gers recent upturn in results.