Evra is battling the likes of Fabio da Silva to keep his place at left-back.
And he told Chinese fans in a Q&A: "To always be fit and play at your highest level, because at United if you play just a normal game you can find yourself on the bench: someone's always ready to replace you. That's why I know I have to work hard every day to fight for my place - even if I'm playing every game.
"The day I stop working hard, Sir Alex will put me on the bench. I know this, which is why I wake up feeling lucky every day and I thank God I'm playing for Manchester United."