Motherwell on Wednesday accepted a club record fee understood to be worth about £3 million but Celtic’s offer to the player has not been accepted.
A spokesperson for Celtic said: “Celtic was pleased to agree a record-breaking fee with Motherwell FC and we have quickly followed this up with a fantastic offer to the player through his agent.
“Currently, we have been unable to come to an agreement with the player’s agent.
“Celtic is content that it has made a magnificent offer and it is now up to the agent and player to decide if the player wants to join Celtic. If not, we move on.”