Mauricio Pochettino and his staff will never forget the debt they owe to Ryan Mason. It was a different age, the first few weeks of their tenure, back in the autumn of 2014. And it feels very distant from where Spurs are now: they are playing brilliantly, have just battered Manchester United and Arsenal at home, and will go toe-to-toe with the mighty Juventus in Turin tonight.

But remember, if you can, a Capital One Cup third round tie at home with Nottingham Forest in September 2014. Pochettino’s Spurs were without a win in four and had lost consecutive home league games to Liverpool and West Bromwich Albion. Hosting Forest, back when White Hart Lane was toxic and anxious, they were 1-0 down. So Pochettino hauled off Paulinho and Benjamin Stambouli to throw on the 21-year-old Harry Kane and 23-year-old Mason, who had impressed for the Under-21s on a cold night at Sunderland just 48 hours before.

With Mason’s first touch, he curled a 30-yarder into the top corner. Spurs went on to win 3-1 and their season – and the Pochettino era – were up and running. This morning Spurs’ official account tweeted a clip of that goal. Assistant manager Jesus Perez commented: “When you changed it all for us mate. We love you, always with you.”

Mason's goal against Forest, and his cameo alongside fellow youngster Kane, was a turning point (Getty)

That is why Mason will always mean so much to Pochettino, Perez and everyone who was there in that first season when it was not immediately clear that things were going to work out at Spurs. Mason provided energy and enthusiasm in midfield alongside Nabil Bentaleb, and finished the 2014-15 season with 29 league starts, a record that few would have expected at the start of that season, when he was a youngster who had struggled with loans and injuries and still needed some direction. “He deserves a lot of credit as he helped us and the team,” Pochettino said. “it is for that that he will always be a special player for me.”

This relationship is why Pochettino, Perez and the rest of the Spurs players were so keen to see Mason after his head injury in January 2017, which following today’s announcement has ended Mason’s career, and why they would still like to help. Pochettino and his staff were in Barcelona on the day when Mason collided with Gary Cahill at Stamford Bridge, and quickly got in touch with Mason’s family and sent him a video message. Then, the day after they returned to London, Pochettino, Perez and academy manager John McDermott went to St Mary’s Hopsital in west London to see him.