Sir Alex Ferguson opens up on how he knew it was time to retire at United

The legendary Manchester United manager has opened up on the most deciding moment that made him retire in 2013.

Fergie had spent a highly a  successful 26 years at the club before announcing his retirement at the end of the 2012/13 League season.

United has previously lost the title to neighbours City, when Sergio Aguero scored a last minute goal to win City their first  Premier League title.

The Scotsman was sure United will win the title next season, and has explained how how he motivated his players to believe they'll win the title next season, even when the season had not started.

"For 30 seconds we were champions.

"I had to walk down the tunnel and John O'Shea was there. He was playing for Sunderland and he saw me and he just said 'Boss, what can I say?".

"I went into the dressing room and I told the players when they were doing any media interviews just to say congratulations to City and that we were going to win the league the following year."

United did win the league the next season, and that was Sir Alex's last title at United. On his retirement, he said:

"I told Cathy (his wife) I was going to retire and she said 'are you sure?"

"I knew it was time because the first time I said I would retire she said 'no you aren't'. If we didn't win the league I don't know what I would have done."