Real Madrid must have been laughing with the money they got because if he was still anywhere near that level they would keep him. Madrid don't just sell players that easily if they are quality, no matter their age. he still just 30 or 31 or something, that's nothing, we've seen them keep the likes of Modric at a much older age and other players
United should have at least been a bit curious as to why they were so willing to sell a player that was such an integral part of their midfield at one point and he was still only 30
Madrid clearly knew that is legs are going and he's only going downhill rapidly