LEEDS UNITED'S Liam Cooper has claimed Marcelo Bielsa's squad are the fittest in the Championship – and that the Whites have learned from last season's defeat to Millwall at The Den.
Bielsa's side are unbeaten and top of the table after six games.
Leeds arrived at The Den last season under Thomas Christiansen in first place, unbeaten in seven games and with six consecutive clean sheets.
But Aiden O'Brien scored to give the Lions a 1-0 win and Leeds lost eight of their next 11 Championship fixtures.
Christiansen was sacked in February and Leeds finished 13th with Paul Heckingbottom in charge, not enough to keep the former Barnsley boss in the job and he was succeeded by Bielsa in the summer.
Cooper added that Leeds are confident they can "run over teams" late in games, and they will face a Lions side that has conceded five league goals in the last 17 minutes of league fixtures this season.
Leeds are currently second favourites behind Middlesbrough to win the title.
"It's brilliant but our biggest thing is that we've been here before with the start last year and that's the biggest thing for me," Cooper said.
"I know the lads will have learned from last season and it's game by game – the next one is the biggest game of our season and we are looking forward to it.
"One thing we know this season is that we are fitter than any team in the league and it's a great feeling to have.
"It's unbelievable knowing that you are going to run over teams in the second half and if the going gets tough and it's the last dying stages."
Millwall did the double over Leeds last season, scoring twice in the last five minutes to win 4-3 at Elland Road in January.
Cooper said: "Millwall is the next game so it's the biggest game of our season and that's the way we have got to approach it.
"They are in our way, they will want to beat us and we know what a hard place it is to go. We will be preparing properly and we will come out of the blocks firing."
Image: Millwall FC