Kieran Tierney has signed a pre-contract agreement with Celtic and he will return to the Scottish club once his Arsenal deal expires. The Gunners had made it clear that the versatile defender, who was signed back when Unai Emery was at the helm, would not be offered a new contract. Tierney has been allowed to talk to clubs about moving as a free agent ahead of next season and opted to turned down overseas or Premier League moves so that he could secure a return to Parkhead, reports the