Derby County have triggered an option extending the contract of left-back Lee Buchanan for a further year, according to reports in the UK.

Celtic have been credited with an interest in the 21-year-old over the past twelve months and, if his current deal had been allowed to run down, the Scottish champions would have had to pay only £300,000 in compensation for the player.

However, with Buchanan’s contract having been extended, Ange Postecoglou’s side would now have to agree a transfer fee to secure the defender’s services.

The Hoops are in the market for a left-back, and they have been linked with Velez Sarsfield’s Francisco Ortega and Hammarby’s Mohanad Jeahze over the past week, so it is not clear whether their interest in Buchanan had already cooled before this latest development.

Derby boss Wayne Rooney has praised the England Under 21 international as a “top, top player” in the past, and he has attracted the attentions of Arsenal and West Ham, in addition to Celtic.