IT was arguably the best performance of Barrie McKay’s career. It was certainly his most famous as he inspired Rangers to Old Firm victory.

From a series of direct, influential runs down the wing to a strike that saw the Rangers End erupt and the penalty that just evaded Craig Gordon’s grasps, it was a day to remember for McKay at Hampden.

And Ibrox legend Willie Henderson knows the winger’s superb showing against Celtic must now be the foundations upon which McKay builds. A new benchmark has been set.

The 21-year-old has been an integral part of Mark Warburton’s side this season as the Light Blues have moved to within 90 minutes of a remarkable campaign.

On Sunday, McKay picked up Rangers’ Young Player of the Year prize and he is in the running to land the PFA Scotland award for the top up and coming talent in the country.

His stunning strike against Celtic, and impressive all round performance, was the highlight of a season that has seen him grab his chance to impress after spells out on loan at Raith Rovers and Morton.

And former Light Blues wing king Henderson hopes McKay can now kick-on once again and become a key player for Warburton’s side in the Premiership next term.

“It is the classic example of how things could have turned out differently,” Henderson said.

“He could have finished up with Morton and all of a sudden he is scoring a fabulous goal against Celtic in the semi-final. His performance against Celtic is the performance that has to be there every week.

“A lot of people a couple of years ago would have thought that performance wasn’t possible. It has now been proven that it is possible.

“He has put in that performance against Celtic and he has got talent. That has been brought out more by the manager since he came in.

“He now needs to have those standards every week. He has to enjoy his football, train hard, work hard and produce it on the field.”

With the Championship silverware and Petrofac Training Cup already placed in the Ibrox trophy cabinet, Rangers now have their sights set on Scottish Cup glory.

If Warburton’s side are to end the campaign with a third medal to their credit, they will have to significantly raise their game from their recent outings as they have lost to Hibernian and Livingston either side of Saturday’s draw with Alloa.

Rangers will bring the curtain down on their league campaign with a trip to St Mirren on Sunday and Warburton will be expecting to see a reaction from his players after a hat-trick of poor performances.

It is understandable that there would be a hangover in the aftermath of a significant and draining run of games that ended with victory over Celtic at Hampden.

But the slump can’t be allowed to continue as Rangers look to rediscover their form before attentions are fixed on the Scottish Cup showdown with Hibernian next month.

Henderson said: “It has been a superb season overall. Some of the performances have been very good and the Celtic game probably topped the season off.

“But you have to remember that it was only the semi-final. It was a great performance and result, but we need a repeat against Hibs.

“It was a huge high against Celtic but sometimes it is easy to let it slip. It is not deliberate from the players, I have been there myself.

“I remember I turned up to Berwick one day to go through the motions and beat them in the Scottish Cup. Well, they are still talking about it today because Berwick beat us. That is an example of what can happen.

“Sometimes the hardest lesson is the best lesson. As Rangers players, along with the manager, they have to accept and know that the last three games haven’t been good enough. The attitude has got to be right for the final.”

If Rangers are right mentally for their sixth meeting of the season with Alan Stubbs’ side, they have a real chance of completing a unique Treble this term.

The Light Blues have already shown what they are capable of when they are at their fluent best and that is the level they will have to operate at throughout the season when they make their top flight return later this year.

And former Ibrox hero Henderson reckons Warburton’s side are starting out from a promising position ahead of an important few months on and off the park.

Henderson said: “One of the things that people need to remember is that the style of the team is down to hard work from the manager, Davie Weir and the squad.

“They have put it in since they came to the club and that is the product. There is nothing to stop them doing it against Hibs, if the attitude is right.

“One of the things that will happen when we move up into the next league is that we will find out how good these players are.

“The games will be more difficult next season every week. They will be playing against the best players and biggest clubs. To combat that, we have to have more performances like that against Celtic and play like that every week.

“To assist in that, I don’t think the manager would complain if there was another handful of players coming into the squad.”

*Willie Henderson was pictured promoting the Rangers Youth Development Company. Since 2002 RYDC profits have been directed to Rangers Football Club’s youth programme - with more than £7 million provided in the last 15 years. Supporters can continue to support the Rangers Youth Development Company in a variety of ways – full details on Rangers Lotto, Rising Stars, Scratchcards, Stadium Bricks and other initiatives can be found at www.rydc.co.uk