Striker Danny Rose has handed in a written transfer request, the club can confirm.
Mansfield Town chairman John Radford said: “I was both shocked and disappointed to receive this transfer request from Danny Rose, especially after we offered Danny a lucrative new two-and-a-half year contract in January, which he signed.
“However, no one player is bigger than Mansfield Town Football Club and there is no justification for keeping a player whose mind has been made up.
“Until any prospective transfer is completed, Danny is contracted as a Mansfield Town player and will only be sold if our valuation of the player is met.
“For the avoidance of doubt, the club will pursue with the football authorities any act designed to induce a breach of contract in order to facilitate the transfer of the player.”