The 39-year-old has only started six Barclays Premier League games this season.
"It can be difficult," Giggs said. "It's just a case of looking after your fitness and making sure you're sharp and not peaking in the middle of the week when you need to be ready for a Saturday game.
"It is tough when you get yourself ready for a Wednesday game, don't play and then you have to get yourself ready for a Saturday game.
"But a lot of players are in that position. We have a big squad and you're not going to play every game.
"Together with Paul Scholes, I probably play fewer matches than a lot of the players but we know we have to be ready when we're called upon.
"My role has changed over the last five or six years. I'm an experienced player and an elder statesman. It's a position I'm quite comfortable with.
"I am helping the young players and whilst I am not starting as many games but it's about being ready when I do."