He said: "The problem is you get a knock from behind, and try to stay up and control the ball, and you end up losing it and not getting a free-kick.
"Then everyone criticises you for not going down. I had that against Aston Villa this season when I was fouled but tried to stay up and didn't get a penalty, so you can't win as a striker.
"Yes, it has got to that stage where there is a win-at-all-costs attitude in the game, and it's a skill now for forwards to win free-kicks and penalties.
"It's like that Ngog penalty for Liverpool against Birmingham. My argument is that if he stands still he gets fouled by the challenge, but by jumping over the tackle he loses the ball, and therefore for me it is a penalty."