New Millwall manager Neil Harris has helped the club rediscover its identity, according to former Lions defender Matt Lawrence.
Harris, 37, was named as manager of the relegated Championship side on Wednesday after a spell as caretaker.
"Millwall fans don't always ask for winning football but they ask for pride and passion," Lawrence told BBC London.
"They were unsuccessful under Ian Holloway and Steve Lomas before him. Neil has instilled the Millwall ethos."
Harris has won two and drawn four of his nine matches in charge of the Lions since Holloway's sacking in March, but he was unable to save the club from dropping into League One.
Lawrence thinks Harris, the club's record goalscorer with 138 goals in two separate spells at The Den, has revitalised the south London club.
"Neil has been a breath of fresh air," he said. "In the last few games he has completely changed the mentality of the team.
"It's readily apparent that the players are willing to work hard for Neil. I don't think that was always the case in the last couple of months of Ian Holloway's reign.
"The Millwall crowd ask for people to be sweating blood on the pitch and that the team cares about the shirt."
Millwall's relegation brings an end to their five-season stay in the second tier but Lawrence believes Harris can build a side capable of challenging for promotion next season.
"Come next year it will be Neil's team predominantly and the players he wants, according to the budget he is given," the 40-year-old said.
"They will be a very good League One side but I'm not saying Neil will be able to shoot them straight back up, although that will be the goal. It is a very competitive league."