Gerard Pique admitted Lionel Messi is a player who can 'change everything' after he stepped off the bench to help Barcelona reach the UEFA Champions League semi-finals.
The Spanish side were heading out of the competition as they trailed Paris Saint-Germain 3-2 on aggregate following Javier Pastore's 50th minute strike when Messi, who suffered a hamstring injury in the first leg, was thrust into the fray.
He immediately transformed a previously tentative home side and the equalised nine minutes after his introduction when the Argentina ace unlocked the PSG defence to find David Villa, who rolled the ball back into the path of Pedro to lash home.
Central defender Pique told Sky Sports: "We are talking about the best player in the world. It doesn't matter if he is a little bit injured, he can change everything and he did again.
"We are really lucky and really proud to have Leo on the team and we have to use him when we are struggling a little bit.
"We knew that for us to have Leo on the pitch was really important. He is our reference, he can score he can pass, he can do everything and he helps us a lot.
"If you have him you have to use him and try to use the best part of him and he helped us a lot."
Barcelona's away goals victory made them the first club to reach the semi-finals of the Champions League for six successive seasons, and Pique is happy to face any of Real Madrid, Bayern Munich or Borussia Dortmund in the last four.
He added: "This club has shown a lot of quality in the last six years. We deserve to be in the semi-finals for one more year. It was really tough and really difficult because they are a strong team, with good quality.
"We are really happy to have qualified for the semi-finals. I don't care who we play, the most important part is to be there. The German teams are really strong and Madrid is one of the best in history.
"It will be tough, but we are in the semi-finals and you expect this when you arrive here."
Dave Jeffrey's men were invited to Glasgow for Wednesday's friendly as a thank-you after the Windsor Park outfit hosted a fundraising match last May following Rangers' administration crisis.
The fixture was Linfield's first ever visit to Glasgow's south side but ended in disappointment as goals from Chris Hegarty and youngster Andrew Murdoch gave the Scots a 2-0 triumph.
The visitors did have a Peter Thompson strike ruled off for offside but for McCoist, the score was inconsequential.
He said: "It was a cruel one on Linfield. They were unfortunate with the offside goal. But with the greatest respect, tonight wasn't about the result.
"It was a thank you for the support Linfield gave us in our hour need. It was a great occasion."
There was only a sparse crows in attendance for the match but McCoist used the occasion to give many of his fresh-faced players their first taste of the 50,000-capacity venue.
After making 10 substitutions, Rangers finished the game with 21-year-old Kal Naismith their oldest player and many of those who featured could yet play a part in the newly-crowned Irn-Bru Third Division champion's league run in following knocks to Barrie McKay and Anestis Argyriou.
McCoist said: "The fact we finished the game with Kal Naismith at 21 as our oldest player tells you where we are. We need players but more importantly we need experience to come in and help them younger lads. It's all very well giving youth a chance but you need to do it when they are protected.
"I was keen to get our young, young ones on, which we did. It was a great education for them. It took most of them five or 10 minutes to get used to the speed and the physical aspect but once they did, I thought they were fine.
"I just hope that's the first appearance of many for most of them. We've got another two injuries with Barrie McKay and Argy so we might need to use them in the run in.
"I won't be scared to throw them in if need be in the next three or four games."
McCoist had been due to hold talks with club chief executive Charles Green this week following reports the manager had been told to dispense with right-hand men Kenny McDowall and Ian Durrant.
But he laughed off a question about a supporter's banner bearing the words "Green out" before exiting his post-match press conference, joking: "Was that inside the dug-out or outside?"
