Son Heung-min hailed Ange Postecoglou as a “Tottenham Hotspur legend” as the club’s supporters’ trust expressed “concern” with another change in manager.

Postecoglou ended Spurs’ 17-year wait for silverware with Europa League success over Manchester United in Bilbao on May 21, but it failed to earn the Australian a third season.

A club statement on Friday announcing Postecoglou’s departure highlighted a woeful Premier League campaign where Tottenham finished 17th, which is their lowest top-flight finish since relegation in 1977.

Captain Son led the tributes to Postecoglou, writing on Instagram: “Gaffer. You’ve changed the trajectory of this club.

“You believed in yourself, and us, since day one and never wavered for a second. Even when others did.

“You knew what we were capable of all along. You did it your way. And your way brought this club the best night it’s had in decades. We will have those memories for life.

“You trusted me with the captaincy. One of the highest honours of my career. It’s been an incredible privilege to learn from your leadership up close, I am a better player and a better person because of you.

“Ange Postecoglou, you are a Tottenham Hotspur legend forever.”

James Maddison insisted Postecoglou’s “winning mentality” was the key factor behind European success.

“Firstly, thank you for bringing me to this wonderful club that I now call my home,” Maddison added.

“Secondly for the Europa League campaign that started in our stadium on game week one and finished perfectly with that special night in Bilbao.

“You led us to victory and we’re European champions and in this club’s history books because of you and your winning mentality.

“Lastly and most importantly is how you are as a man and a person. Your unwavering self belief and strong mindset is infectious and a massive reason in why you were the man to end this club’s 17-year drought for a trophy.”

Goalkeeper Guglielmo Vicario was Postecoglou’s first signing, he said: “You are not only a top manager, you are an incredible person to work for, a real leader, a mentor, and someone I’ll always look up to.”

Dutch defender Micky van de Ven added: “Gaffer, thank you for everything! Believed in me from the first day I arrived at the club.

“You kept believing in us and kept pushing us. Big part of the success from the club this year, and forever grateful that you made me part of it.”

Striker Dominic Solanke signed for Spurs last summer in a £65million deal.

“Thank you for bringing us a wonderful trophy. (I) won’t ever forget the convo we had before I signed and we achieved a dream,” Solanke posted.

Right-back Pedro Porro insisted the 59-year-old would “always be celebrated”, writing: “Thank you for everything, boss.

“I’ll always be grateful for the way you led us, defended us, and kept us going through all the highs and lows.”

Forward Richarlison added: “Everyone who loves the Spurs will remember that Big Ange always bags trophies in his second season.”

The Tottenham Hotspur Supporters’ Trust thanked Postecoglou for an “amazing night” in Bilbao but acknowledged league results were a “long way short” of expectation.

“Our concern now is that it appears we will have yet another change of direction,” a THST statement read.

“We can only hope that the right decision has been made and that the new manager is fully supported by the board and everyone at the club to build on the cup success that Ange has lain.

“He will need the finances to build a strong squad that can challenge simultaneously on many fronts. We wish whoever is appointed well. Spurs fans have had a taste of glory and we don’t want to wait another 17 years for more.”

Brentford boss Thomas Frank is reported to be the leading contender to take over, with Crystal Palace’s Oliver Glasner, Fulham manager Marco Silva and Andoni Iraola of Bournemouth also linked with the post.