Ole Gunnar Solskajer took over at United in December following the sacking of Jose Mourinho.
The Norwegian will manage his old side until the end of the season, when executive vice-chairman Ed Woodward will appoint a permanent boss.
Solskajer played for United for 11 years, under the tutelage of legendary manager Ferguson.
Ferguson was reportedly brought into the Old Trafford dressing room earlier this month to give a rousing speech to Solskjaer’s players.
And the 45-year-old has spoken about the most valuable advice that he’s received in recent weeks from his former gaffer.
“The hunger to improve, the hunger to win. To get up next morning, if you win or lose, to try and improve the club,” he told Sky Sports’ Soccer AM.
“He is the best ever, I would be stupid to not try and learn from him.”
Solskjaer’s side face Tottenham on Sunday evening in the weekend’s crunch Premier League clash.
Tottenham manager Mauricio Pochettino has been heavily linked with taking over at United when Solskajer’s time is up in the summer.
The match-up will be Solskjaer’s first big test since his return at Old Trafford.
Their first five games have all ended in victory, scoring 16 goals in the process.
But Spurs will prove a different test on Sunday, with the last game between the two sides ending 3-0 to Pochettino’s men.
Speaking about the task United face on Sunday, Solskjaer noted that his players can’t show an naivety if they want to win the game.
“When you play against a good team you have got to defend. You have to earn the right to win a game of football,” he added.
“We’re not going to go gung-ho and be naïve but Manchester United is about attacking football.
“We’ve got to go there and attack the game, we have to win to stand a chance of passing them in the league. We go there to take three points.”