The Reds have reportedly been in contact with the Dutch club regarding Suarez, however the clubs' valuation of the player is believed to still be some way apart.
The Merseysiders are anxious to add fire-power to their line-up as they have been over-reliant on Fernando Torres this season which has seen them fall down the Premier League.De Boer told De Telegraaf that Suarez will not be allowed to leave Ajax unless he is sure a replacement for him can be found before the end of the January transfer window.
He said: "We won't let Luis [Suarez] go on 31 January at 23.55. It is logical and a deal which I made with Rik van den Boog [general director of Ajax].
"To replace Suarez will be difficult, but we are ready. We have a Plan B, we know what we want if he leaves."
De Boer’s side have been linked with moves for Bas Dost of SC Heerenveen or Eidur Gudjohnsen of Stoke City if Suarez does complete a move away from Amsterdam.