Keane’s record as one of the greatest Premier League players was established in a dominant United career from 1993 to 2005.
The Irishman won seven Premier League titles, including five as skipper, alongside four FA Cups and a Champions League triumph, at Old Trafford.
However, the end of his United career was soured by a breakdown in relations with Sir Alex Ferguson, as he joined Celtic in December 2005, after leaving the Premier League giants by mutual consent.
His decision to join Celtic fulfilled a boyhood dream for Keane but he received offers from across Europe as his United career came to a sudden conclusion.
The former Nottingham Forest star stated in his autobiography ‘The Second Half’, Real Madrid director of football Emiliano Butragueno reached out to him, but he opted against a move to Madrid.
“Butragueno said, ‘Roy, we’ll be glad to have you’. The board just had to sanction the deal, it was standard procedure”, as per quotes from Mundo Deportivo.
“I should have appreciated Real’s offer more. It was the most attractive challenge in front of me.
“I was too negative. The weather and training might have given me a new lease of life and another two years of playing.
“I was looking at what might go wrong, and at the time, it felt like the right decision.
“I didn’t want to move to Spain. It was fear of the unknown that decided it for me.”