Mauricio Pochettino says Ole Gunnar Solskjaer has made a shrewd move by getting Sir Alex Ferguson back involved with the Manchester United first team.
Interim manager Solskjaer invited Ferguson to the training ground to speak to the players as he bids to turn around fortunes at Old Trafford.
"It is fantastic news because he is football, Sir Alex means football. For him to be involved is massively important," said Pochettino, whose Tottenham side face United on Sunday, live on Sky Sports Premier League.
"Did you send best wishes when he was ill? Yes, I did. I cannot hide my admiration and relationship with him. He was one of the people I admired the most, an inspiration.
"We had a very nice lunch in London [in 2016] and since then we have kept a good relationship. We are football people.
"Has Ferguson given United a new energy? He is the best manager in the history of football. To see him every day is massive. He is an encyclopaedia of football."
United dominated Spurs during Ferguson's days in charge and one of his pre-match team talks has gone down in football folklore.
Roy Keane recalled: "Ferguson came in and said: 'Lads, it's Tottenham', and that was it. Brilliant."
Those one-sided days are gone, though, with Spurs seven points ahead of United in the Premier League table and seeking a third successive league win over the Red Devils.
"We've beaten them the last three times at home in the Premier League - twice at White Hart Lane and once at Wembley," said Pochettino.
"I don't know what happened in the past but games like Tuesday's semi-final against Chelsea please me a lot. Maybe our performance wasn't the best but we competed very well.
"The team is very competitive, that is true. I don't know if that was the case in the past between the two teams."
The days of United signing Spurs' best players also appear over. Teddy Sheringham, Michael Carrick and Dimitar Berbatov were among those who swapped White Hart Lane for Old Trafford and Pochettino credits chairman Daniel Levy for stemming the exodus of key players.
"He is not an easy person to do business with," said the Argentine.
"You have to give him credit because when he came here 16 years ago Tottenham was a completely different club. They were mid-table, and mid-table for facilities.
"But today we are in the top for facilities and for the last few years the club is fighting against the big sides."