JIM Duffy’s well-known affection for and former association with Celtic mean that, in the coming days, the Morton manager won’t be among those considered for the vacancy which has suddenly arisen at Ibrox.

But Rangers could do a lot worse than appoint as a replacement for Mark Warburton an individual who was responsible for giving them quite a scare at the end of what has been another rather difficult week.

A Kenny Miller strike and a second-half goal from Martyn Waghorn secured a 2-1 win and safe passage to the last eight of the William Hill Scottish Cup, where Rangers will host either Dunfermline or Hamilton Academical, but they were certainly made to work for their victory.

Morton have been the surprise package in the Ladbrokes Championship this season. They are currently in fourth place in the table and seem certain to, at the very least, secure a play-off spot. They showed exactly why in this fifth-round match yesterday. They silenced the home fans, and sent the large travelling support wild when they snatched the lead early on, and they could have earned a replay if they had showed more composure up front.

Morton took the lead in the seventh minute when Clint Hill failed to head a speculative Ricki Lamie punt upfield to safety and then Andy Halliday had possession stolen from under his nose by Michael Tidser who nipped in and fed the ball to Aidan Nesbitt ahead of him. Nesbitt scooped the ball back to his team-mate who struck it first time on the volley and watched as his low curling effort squirmed past Wes Foderingham.

Morton only remained ahead for six minutes. The home team equalised after Barrie McKay had burst through on goal and forced Derek Gaston into making a decent save. Miller pounced on the rebound and drilled a shot into the net off the legs of Thomas O’Ware.

Rangers should have edged in front after that. Emerson Hyndman struck the crossbar with a delightful chip over Gaston from outside the box, Jason Holt headed wide and McKay also missed from an acute angle. However, Morton impressed and deserved to go in level at the break. They competed ferociously for every ball and sought to attack whenever they won possession.

In the second half, Holt tested Gaston with a shot from outside the Morton box, but it was the visitors who should have reclaimed the lead after being gifted a chance by Philippe Senderos.

The Swiss centre-half headed the ball straight to Tidser who quickly sent Nesbitt clean through on goal, but with just Foderingham to beat the on-loan Celtic youngster snatched at his shot and fired high into the stands.

It took an excellent passing move to put Rangers in front. McKay started it off with a cute backheel, Holt supplied Hyndman, whose shot was palmed into the path of Waghorn by Gaston and the striker made no mistake from a few yards out. It was his 11th strike of the season, but his first in nearly two months.

Gaston did well to deny James Tavernier and Waghorn to keep Morton in touch. The second tier side then had two chances to restore parity. Good work by the lively Nesbitt set up Jamie Lindsay, another player on loan from Parkhead, and he went agonisingly close with a shot from just outside the area.

A mix-up between Foderingham and Lee Hodson, who had taken over from Lee Wallace when the Rangers captain had hobbled off moments earlier, then allowed Ross Forbes to nick the ball and square to Luke Donnelly.

The substitute, who arrived on loan from Celtic last week, had an open goal to aim at but with Hill bearing down on him snatched at the ball. His attempt, as Nesbitt’s had earlier, sailed high over the goal.