The Old Trafford mastermind cannot choose the best as he provides a handful of top names while having a pop at player agents during transfer dealings
The Premier League boss has seen his fair share of stars pass through his hands during a glorious career at Old Trafford.
And he has picked a handful of names he believes have been the greatest under his leadership.
"Who is the strongest player I have coached? I cannot pick one in particular, but Eric Cantona, Cristiano Ronaldo, Paul Scholes and Ryan Giggs have been fantastic," Ferguson told reporters during a speech he gave at the University of Tor Vegata, located in the Italian capital Rome.
Speaking of the transfer market, United were keen on Inter's Wesley Sneijder, but the move never took flight, Ferguson said: "Regarding the transfer market, the player is never there when it is time to negotiate.
"Sometimes I wonder whether agents work for themselves or for the players."
On the Premier League's meteoric rise over the years compared to Italian and Spanish football, the coach added: "English football is going through a good moment and I hope this continues, but there has been a rise from the big Spanish clubs [in Europe]."
Manchester United play Bolton Wanderers on Saturday in the Premier League.