Celtic claim a fee was agreed with Manchester City for John Guidetti prior to them taking the striker on loan.
Xabi Alonso claims no Premier League offers were put to him before leaving Real Madrid for Bayern Munich.
Axed Manchester City boss Roberto Mancini has not ruled out a move to Napoli following his dismissal from the Premier League club on Monday.
The Italian, who guided City to FA Cup and Premier League triumphs during his time in England, has been linked to a number of clubs since his departure, including Monaco, Paris Saint Germain and a rejuvenated Napoli.
Currently in Naples, Mancini told Sky Sport Italia a move to Serie A club Napoli, who are fast emerging as the biggest threat to Juventus, would not be off the cards.
"Napoli is a great team which has a great coach," he said.
"Me on the Napoli bench? In my job never say never.
"But I'm here for personal reasons and not to meet (Napoli president, Aurelio) De Laurentiis."