Ole Gunnar Solskjaer hopes to replicate the spirit of Manchester United's treble-winning season to lift the club back to the top.
Solskjaer famously scored the injury-time winner in the Champions League final when Sir Alex Ferguson's United side scooped three trophies in 1999.
Now the Red Devils manager, the Norwegian intends to build the side around the principles that worked so well 20 years ago.
Solskjaer told ESPN FC: "We challenged each other every day in training. There were fights and there was an inner justice that I've not seen in too many teams.
"We never, ever accepted anyone being below par in training. We kicked each other and we had to win every single day. That moved over into games and we never gave in. There was an unbelievable team spirit.
"I want my players to really push each other and demand 100 per cent attitude from each other every single day. That's the only way you can improve and it's the only way you can win.
"We had something special. It's a different group now and the challenge is, 'How can I make these players winners as we were?'"
United are currently sixth in the Premier League but are just three points behind third-placed Tottenham and are still in contention in the Champions League.
They face LaLiga leaders Barcelona in the first leg of their quarter-final at Old Trafford on Wednesday.
United are not the favourites for the tie but Solskjaer, who oversaw an impressive comeback victory over Paris St Germain in the last round, is confident.
Solskjaer said: "We're playing against a good team but there is something special about this group of players. It will be fantastic."
