Kris Boyd has been described as 'irreplaceable' by Rangers team-mate Steven Naismith following the striker's cup heroics in his side's dramatic win over St Mirren.
The Gers looked set to be heading for extra time in Wednesday's Active Nation Scottish Cup replay encounter at Ibrox, only for Boyd to pop up with an 86th minute winner that booked Walter Smith's side a place in the last eight of the competition.
Naismith admitted the Rangers team had missed Boyd during his recent absence from the side following a double hernia operation, and heaped praise on the 26-year-old after he bagged his 22nd goal of the season.
"Boydy is just unbelievable in the box," Naismith said. "He's had a chance and put it away and that's why he is a vital player for us.
"He is massive for us. If you take his goals away, we lose a massive part of our team.
"When he was out with his hernia, the boys who came in did a good job. But you can't replace somebody of Boydy's quality."
The strike pairing of Boyd and Kenny Miller has yielded 37 goals this season, leaving Naismith in the background as the Glasgow giants make progress to a clean sweep of domestic trophies.
The frontman admitted he was relieved to feature in a side that made six changes from the 3-0 defeat of Hibernian and highlighted the benefits of having extra competition for places in the squad.
Naismith conceded complacency had crept into some performances during the campaign, but said Smith's charges were eager to prove they are worthy of a place in the starting XI.
"It was good to get back in the team," he added. "I faced the consequences of a bad game against Motherwell and I wasn't stripped at the weekend so it was good to get back in and I thought I did all right."
"It keeps everybody on their toes now. We have been through phases in the season where there hasn't been much competition for places and the performances have maybe been a bit flat.
"But, with everybody back fit, everybody is putting everything into training and the manager is going to pick the best 11."
Rangers will face St Mirren again in next month's Co-operative Insurance Cup final, when both clubs will contest the first major trophy of the season.
But despite also sealing a quarter-final berth in the Scottish Cup and sitting 10 points clear in the SPL, Naismith still refused to talk up the prospect of claiming a domestic treble.
"It was important just to get into the next round - that's usually the philosophy in the cup games," he said. "We knew the first game wasn't the prettiest and this would be another tough game. We are just glad to get through.
"It's great to get into the next round and now we can just concentrate on the next league game. We will not get carried away with trebles or anything like that.
"We will just focus on each game as it comes and hopefully we win more than we lose.
"We don't take into consideration what each competition is - we just know we need to go out there in every game and put a performance in and get the victory."