Millwall manager Neil Harris says he needs to overhaul his squad this summer as some of this players are “not professional enough”.
The Lions are 21st in the table, but have secured a third successive season in the Championship.
“Too many players have let me down this year,” Harris told BBC Radio London.
“Some players have maxed out what they can do, some players need a fresh start and some players don’t want to play for the club and I want to move them on.”
Milwall finished eighth last season, just three points off the play-off places, after coming up from League One in the summer of 2017.
However, the Lions have struggled for most of the current campaign, but their survival was confirmed with two games to spare after Rotherham lost at West Brom on Saturday.
“The gulf between League One and the Championship is the biggest it has ever been and it is only going to get bigger,” 41-year-old Harris said, following Tuesday’s 2-1 home defeat by Bristol City.
“I think this year the reality check has kicked in.
“We all got carried away last summer and everybody expected us to just go again and be a top-half team, but you can’t keep getting away with it and we need to invest in the squad.”
Harris, who spent 11 years playing for the club and is Millwall’s record goalscorer, has been in charge at The Den since March 2015.
He wants to recruit players who are “committed to the club” and “buy into” his work ethic.
“If we can’t afford the best players in the division, can’t afford the best facilities and can’t have the strength in depth that is needed at times, then we need to get the best characters,” he added.
“The majority of my lads are good characters, but some need to go.
“There will be a surprise element to some of the players that leave, but they need to move on because they will not buy in to what I want to achieve.”