Veteran winger Giggs is just 33 games short of breaking Charlton's record of 759 matches and United boss Sir Alex Ferguson believes the 33-year-old will surpass that feat.
Giggs has put pen to paper on a one-year contract extension. But Fergie reckons Giggs - who has won nine Premier League titles - is more likely to break Charlton's record next season rather than during this campaign.
"We've got 29 league games left, hopefully another 10 or so European ties and the FA Cup, so it's possible this season," said Fergie.
"But Ryan won't play every game. He'll be here next season, so this season or next he will do it.
"The way he looks after himself, Ryan could go for infinity. I just don't see any marked deterioration in the lad.
"He's 34 in November and when a player gets to that stage, you look to see if they have lost this or that. But there's not really been a downturn. He's unique."