The striker is set to return against St Mirren on Sunday.
The striker has been absent since February after picking up an injury in the Scottish cup game with Kilmarnock.
He has been sorely missed as well, with his 28 goals so far this season having played a big part in the Gers success so far under Mark Warburton.
His absence his teammates have managed to secure their promotion to the Scottish Premiership, with the Petrofac cup and beat rivals Celtic in an Old Firm cup semi final.
And he admits that while it has been frustrating to miss out, it has been exciting being able to watch with the fans.
“It’s been tough watching from the sidelines,” he told rangers.co.uk.
“When we won the league, the Petrofac Final and then the Celtic game without me it’s been frustrating to watch. However the boys have one such a great job. It’s been exiting watching as a fan and taking in the atmosphere.”
The striker will now be determined to get himself fully fit in time for the cup final against Hibernian at Hampden.
He will have 20 days to do so following the game against St Mirren on Sunday and would prove a huge boost to manager Mark Warburton’s plans to make it a treble in his first year at Ibrox.