All my players say
The playoff transfer deadline has passed. This player will not be eligible to play in the playoffs if purchased by another team.
Does that mean I can no longer buy a transfer list player ?
It means that if you want to sell a player that player can't be used in Playoff for the buyer now.
If you buy a player before 20th (not sure what time but read other messages) you can use that player in Playoff because he was transfer listed before today.