The boss looks ahead to this weekend's big game
Neil Harris has warned his Millwall squad that they can expect a much-changed Bradford side from the one they played last season at The Den on Saturday.
The Lions met The Bantams on four occasions during 2015/16 - including twice in the League One Play-Off Semi-Finals - but it has been a summer of transition at the Coral Windows Stadium following the departure of Phil Parkinson and subsequent arrival of new boss Stuart McCall.
The West Yorkshire club are unbeaten so far this campaign and visit SE16 a point ahead of Millwall in second place.
"It's a completely different Bradford team to last year," Harris said.
"Before they were very aggressive, big and direct, but Stuart's gone in there, had an overhaul and they've done fantastically well. It's not a complete change of personnel in the team but there has been a high turnover of players and they play a lot of attractive football. They are a huge threat going forward.
"It's going to be a tough one for us - a good challenge which we look forward to.
"The international break means we are without a couple of players but I'm delighted to be playing the game because on the back of some victories in a row it's important to continue our momentum.
"It's a big game at this level between two in-form teams."
Millwall were one of few clubs inactive on transfer deadline day earlier this week as The Lions kept hold of their most prized assets despite a summer of speculation. That has pleased manager Harris, who has heaped praise on chairman John Berylson for his commitment to overseeing a bright future for the club.
"I'm one of the managers who is quite happy that the transfer window is shut," Harris added.
"The chairman has been brilliant. He said to me in the summer that we will not sell anybody unless it's right for the club.
"There has been interest in some of our players because they are good players, but no one has asked me to go which makes it easier for us.
"There has been a lot of speculation, paper talk and phone calls so to get to today with this group of players is testament to John and the board and their desire to want to build something for the future."