Manchester United manager Ole Gunnar Solskjaer wants his players to replicate the spirit of the 1999 treble-winning squad.
Solskjaer famously scored an injury-time winner in the Champions League final against Bayern Munich as Sir Alex Ferguson's team claimed an unprecedented treble in 1999.
The Norwegian, now permanent manager at Old Trafford after signing a three-year deal with the club, wants to build his team with the same 'winning' spirit of 20 years ago.
Solskjaer told ESPN: "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 face Barcelona in their Champions League quarter-final first leg at Old Trafford on Wednesday and Solskjaer is confident of causing an upset against the runaway La Liga leaders.
He said: "We're playing against a good team but there is something special about this group of players. It will be fantastic."