Celtic manager Brendan Rodgers says he rates Kieran Tierney alongside Danny Rose and Ryan Bertrand as Britain's best full-backs.
Rodgers praised Tierney's performance in opposition to Bayern Munich's Arjen Robben in Celtic's 2-1 defeat.
"I've worked with who I consider to be the two best full-backs in Britain - Danny Rose at Watford and Ryan Bertrand at Chelsea," said Rodgers.
"And Kieran is right up there with those boys."
Rose, 27, now at Tottenham Hotspur, and Southampton mainstay Bertrand, 28, are both experienced England internationals.
But Rodgers believes that Scotland left-back Tierney, who a day earlier had signed a new six-year contract, is not yet the finished article.
"He's still very young, still got bits of improvement to make, but his quality, will, determination and focus is outstanding," he said.
"He loves playing at Celtic and nights like this you can see why. He's a real special talent who is focused on improving.
"He's a really special player. For 20, to play at that composure - first and foremost, he's a defender."
Celtic's loss in Glasgow means Rodgers' side cannot reach the knock-out stages, but striker Leigh Griffiths believes the Scottish champions proved they are good enough to compete with Europe's best.
"They were poor goals," he said. "It's cost us dearly, but everybody saw that we can play at this level.
"On our day, we can run anybody close.
"We just need to take that kind of performance over to PSG and hopefully try and frustrate them for a long period of time."
Celtic are favourites to clinch third place in Group B and drop into the Europa League and Griffiths believes that will be a job well done.
"Our aim at the start of the season was to be in European football after Christmas," he said.
"As long as we don't get beat from Anderlecht at home we should progress."
Meanwhile, Moussa Dembele, who started the game ahead of Griffiths, also thought Celtic proved they could compete with the tournament's top sides.
"It was a good game from both teams," he said. "This game is just about small details and today we concede two easy goals and that's cost us the game.
"We can't give these players these kind of chances.
"We showed that we have the desire and the quality as well to be in this competition. We just have to keep doing it again now.
"We made it tough for them and we showed our quality."
Celtic travel to group leaders Paris St-Germain on 22 November and end the group campaign at home to Anderlecht on 5 December.