And he claims he was more disappointed with the Van Persie transfer to United in 2012 than when Fabregas left the club a year earlier.
Frimpong told Meta Ratings: “I think I was more disappointed when Robin went to Man United because at that time he was the captain and he was the best player in the Premier League, and losing Robin was much more of a blow than losing Cesc because Robin was bringing goals to the game, he was winning us games.
“He was playing really well for us at the time so I feel like he was a big blow at the time, and more than when Cesc left.
“These things happen in football, and you can't control it.
“It's something that is difficult for the club when you have players who are on less than a year's contract, they want to leave and you want to make money; it makes sense."