Scotland striker Kenny Miller is holding talks with Derby after Celtic accepted an offer from the Barclays Premier League club.
Miller, 27, moved to Celtic from Wolves on a free transfer last summer but struggled for goals in his first season.
Celtic signed Scott McDonald and Chris Killen earlier this summer and also have Jan Vennegoor of Hesselink, Maciej Zurawski and Derek Riordan as attacking options.
Derby manager Billy Davies had been keen on Southampton striker Kenwyne Jones before the youngster moved to Sunderland in a £6million deal.
Miller, who joined the small band of players to have appeared for both Celtic and Rangers, has hit three goals in his two appearances for the Hoops this season.
Scotland boss Alex McLeish admitted it could become a problem selecting Miller if he is not playing club football at first-team level.
McLeish has so far kept faith with Miller, fielding him against South Africa at Pittodrie last week and then including him in the squad for the upcoming Euro 2008 qualifiers against Lithuania and France.
Celtic boss Gordon Strachan said: 'I like good players around me but the club has accepted a fee and Kenny might think that it's better to get a regular first-team place somewhere.
'He has been fantastic for us. Even when he was not at his best he was a great team-mate, good in the dressing room and he showed earlier in the season what a good player he is.'