Van Persie has made an incredible impact at United following his 24 million pound move from Arsenal in the summer, scoring nine goals in 12 appearances, and now faces his old Gunners team-mates at Old Trafford.
But Ferguson could have got the Dutchman back in 2001, when he dispatched one of his scouts, Jim Ryan to Holland to watch the teenage striker in action for Feyenoord.
However, Van Persie, who was red carded in the game, raised concerns about his skills, despite his obvious talent.
"Robin was only 16 or 17 at the time. But our assessment of young players is always based on the potential you see in them," the Daily Mirror quoted Fergie, as saying.
"We sent Jim Ryan over to Feyenoord and Robin was actually sent off in the game. Jim said he was a fantastic talent, but felt that he was a little immature. At 16, we're all immature, but we didn't progress it, and then he went to Arsenal," Ferguson added.
As a result, the United boss decided against signing van Persie, and watched Arsenal land him in 2004 for what proved a bargain 2.75 million pounds.
Ferguson finally landed the Gunners star almost 11 years later after the 29-year-old refused to sign a new deal with Arsenal.
"I never thought we would get him, until he convinced us that he wouldn't be signing a new contract at Arsenal. We just started working hard with Arsene Wenger and myself, I phoned him quite a few times, and we eventually came to an agreement," Ferguson said. (ANI )