Juan Roman Riquelme has revealed that Manchester United tried to sign him in 2006 -- and said that turning Sir Alex Ferguson down was the only regret of his career.
The Argentine had helped Manuel Pellegrini's Villarreal team reach the last four of the Champions League when he said United attempted to buy him.
But the playmaker opted to stay in Spain and missed out on playing his part in a hugely successful period for United.
"The only thing I regret in my career was a decision that I took, when at the hotel in England before the semifinal with Arsenal, when Manchester United came to buy me and I said no," Riquelme told Mundo Deportivo.
"I stayed at Villarreal, because I was very comfortable with my teammates."
United won the Premier League in each of the three seasons after they tried to buy Riquelme and reached two Champions League finals, triumphing in 2008.
With Riquelme staying at Villarreal, Michael Carrick became United's only major signing in 2006.
Riquelme, who helped Argentina win the 2008 Olympic gold medal and three Copa Libertadores title with Boca Juniors, retired last year after a career that included two spells with the Argentine giants, one year at Barcelona and five seasons in Villarreal's colours.