Rooney has yet to score from open play for Manchester United this season and, after having played a key role in United's title challenge in the last campaign, there has been plenty of talk about his dip in form.
There have been suggestions that problems with his private life are to blame, while Sir Alex Ferguson feels he is feeling the pressure of being in the spotlight, but Giggs is convinced his quality will ultimately shine through.
"In my experience the only way to deal with it is to go on the training pitch and work hard," he said. "The rest will eventually come because the quality is there.
"When you are playing at United, you are there to be shot down. All you need is to lose a bit of form or you have a few injuries that mean you are not quite firing.
"Wayne set such high standards last season. He was winning games on his own. We knew it could not carry on. At the moment he is not scoring goals, but that will change quite soon because he is a world-class player."
ESPN analyst Kevin Keegan has said Rooney's confidence is "shot", but Giggs said: "I don't see a confidence issue.
"When you are scoring goals you think you are going to score every game. That has always been the same, but it is not a worry, for Wayne or United as a team. We have never tried to rely on one player.
"Hopefully that will be the case this year."
Reports suggest Rooney is ready to return for United against Sunderland this weekend despite Ferguson having earlier ruled him out.