Giggs, 34, said: "Getting criticism is part of being a Manchester United player. It doesn't bother me.
"I don't know why I'm singled out. Maybe it's because I've been around so long.
"But the one person I have to impress is the manager - and while he is picking me, I know I am good enough."
Giggs admits he cherishes each game now more than ever, knowing the finishing-line is near.
He admitted: "When you are young, you think you'll get another chance. At 34, you know there are not many chances left.
"I've been enjoying my football more than ever since I turned 30, probably because I know I'm close to the end.
"Right now, though, you do think 'This could be my last trophy' or 'This could be the last big game I play in'."