However, Ferdinand revealed that United were also interested in the Dutch winger and believes that it would have been a "great" signing had Robben's visit to the training ground been more successful.
"What a player. Robben was great. We should have signed him at Man United. I think he came to the training ground. He walked around and didn't like the smell and walked off and went Chelsea. I couldn't believe it, man. He would have been great for us," Ferdinand said during a Q&A on his Instagram page.
"You knew he was going to come back in on his left but the left-back couldn't deal with it,. He'd be saying, 'I'm going to come in on my left, you're not gonna stop me'. And they didn't."
Robben hung his boots up at the end of last season following a career which saw him win 30 trophies, including 12 league titles in four different countries.