There are a couple possibilities, one is the guy who has the player has "rejected all offers", or maybe they are on a different server (which seems less likely)

I haven't got anyone off the list, myself. But I can usually to make a bid on all the players on my list. You can also bid on your friends' players if they are on the same server (if you can see their fixtures) and really any teams' guys in any of the competitions you are in that the player is 3* to 5* from your perspective.