Nottingham Forest boss Nuno Espirito Santo credits former Reds manager Brian Clough for giving the club “the mentality of knowing that anything is possible in football”.
It has been 20 years since club legend Clough died at the age of 69 in 2004.
During his 18-year spell with Forest, he took them from Division Two to winning the First Division title in 1978, followed by two consecutive European Cup wins in 1979 and 1980 and four League Cup trophies.
“It is present in us every day. We go around the club and we see how Brian Clough was important for Forest,” Nuno told BBC Radio Nottingham.
“What he achieved and how things change. The mentality of knowing that anything is possible in football and that is credit to Brian and the players of that fantastic moment.
“There is so much to learn if you go deeper and try to understand the evolution of the game. [Arrigo] Sacchi, for example, and his great Milan team, in Portugal with Sporting, Real Madrid. If you go deep and understand how the game has evolved and now is going back again it is curious.
“But of course, me personally I try to go 30 or 40 years back and you can still find some videos and footage. You can see what football players did then because they played with freedom.”