Form is temporary, class is permanent. In the case of Niko Kranjcar, it was his fitness and attitude that were in question rather than his ability.

Boss Mark Warburton never had any fears, though, and the Croatian has already gone some way to convincing any doubters amongst the Rangers support.

A second half cameo against Motherwell on Saturday was followed by an hour in the win over Annan on Tuesday night as Kranjcar has made an immediate impression in Light Blue.

Read more: Mark Warburton pleased Rangers stars have followed his lead by penning new Ibrox deals

It is, of course, still very early in the campaign and there will be far greater challenges to come for the former Portsmouth and Tottenham star, but the initial signs have given Warburton and the Ibrox crowd plenty of reasons to be encouraged.

The Gers boss spent time in New York with the midfielder earlier this year and convinced him to make the move to Ibrox.

And he is confident there is plenty more to come from one of his highest-profile signings of the summer.

Warburton said: “I just saw a very talented player. You look at where he was before – was it the right environment for him? I don’t know.

“He went back to Kiev and I believe they had a really settled squad doing well. When that happens you are loathed to change it.

“I think he found that bit hard. You want to hear it for yourself. I went to New York and had dinner with him and knew within 10 minutes that the fire still burnt very strongly.

Read more: Mark Warburton pleased Rangers stars have followed his lead by penning new Ibrox deals

“What we need to do is make sure we keep that fire well lit. If there are 50,000 at Ibrox, that’s the kind of stage where talented players want to play.”

Kranjcar, as you would expect, looked a class apart as he dictated play on Tuesday night, a series of quick turns, neat flicks and precision passes earning him a standing ovation as he was replaced by Joey Barton.

Warburton knows there were pre-conceived judgements about him signing a 31-year-old from the North America Soccer League but Kranjcar insisted he had the heart for the fight in the Premiership when he put pen-to-paper on his Ibrox deal last month.

And the Ibrox boss is pleased to see his summer signing catch the eye in his first outings as preparations continue for the Gers’ top flight title challenge.

Warburton said: “He’s 31 and has 81 Croatian caps. If we can get him to where he can be he can add to those.

“What a talent he is. He showed that [on Tuesday night] and the boys responded.

“He’s working really hard, the staff are working really hard with him as are the players.

“Touch wood, he’ll keep improving but the technique and talent is unquestionable.

“That’s a massive discussion. A player could turn round and say to you ‘I’ve always had calf problems’.

“Why? Has it always been that every six weeks you pull your calf? If so, what can we do here in terms of strengthening, core or whatever it takes.

“Sometimes you can get pre-conceived ideas. The obvious thing is, you play on Friday then it’s Astroturf… that won’t suit him. Well why not? We train on it in here enough times.

“As a manager you can get lulled into this thing – 30 plus, Astroturf. I’m not sure.”

Read more: Mark Warburton pleased Rangers stars have followed his lead by penning new Ibrox deals

Having seen Kranjcar take a starring role and given Barton a rousing welcome to Glasgow, Rangers fans will soon get the chance to witness another of Warburton’s new recruits in action.

Midfielder Jordan Rossiter has been one of the stand-outs for the England Under-19s as they have progressed to the semi-finals of the European Championships this summer.

And Warburton is keen to see the former Liverpool protégé in Light Blue when he brings his national service to an end.

Warburton said: “He’s playing against Italy [today] in the semi-final with the final on Sunday so Jordan will be back here no later than Monday – and I hope for his sake it’s Monday.

“He’s had a great tournament. The feedback has been really positive and he has been keeping some really good players out of the team.

“So we will be getting a player back who is match fit and on good form which is good news.

“He will come straight back in and he wants to because he has signed for a new club. He’s keen to play.

“He missed a chunk of last season at Liverpool with an ankle injury so he’s a bit like Waggy. He’s desperate to get going and he’s had his holidays.

“If England do well the he is in the World Cup next May so that’s something we will have to look at in terms of his load next summer.”

With Rossiter to return, Matt Crooks recovering from injury and two more additions still to be made, the Rangers squad is all-but complete for the new campaign.

Warburton has added strength and depth to his Ibrox ranks and now he has competition for places and a strong hand to play in the Premiership.

He said: "One of the big things over the summer was to look over our shoulders at the options from the bench.

"On Tuesday night on the bench we had Kenny Miller, James Tavernier, Joey Barton, Harry Forrester, Jason Holt and Wes Foderingham so we’re in a good place.

"The bench is stronger and the squad is definitely stronger. We’re pleased with the balance so far although it’s got to gel yet."