Fergie: Giggs will be offered new deal
Giggs, 38, is United's all-time leading appearance maker having played almost 900 times for the club since making his debut in 1990.
The Welshman has been on a rolling contract since the age of 30 but despite Giggs' former team-mates Gary Neville and Paul Scholes retiring last season, Ferguson believes his veteran midfielder can go on for another year.
"I think Ryan can play another year,'' Ferguson said. "There is no evidence at this moment in time that his energy, stamina or speed are decreasing. In fact, it's exactly the same as it was the last two or three years. It's amazing.
"I know it's mid-season now and it all depends on what Ryan thinks about his future, too. He knows he can't go on forever, we know he can't go on forever, but he can play for another year.''
Meanwhile, Ferguson has backed Michael Carrick, Giggs' central midfield partner in last Wednesday's 5-0 win at Fulham, to step up and become United's most integral player after some excellent displays in recent weeks.
"Michael's been one of our best players over the past few weeks,'' Ferguson said. "He's been instrumental in what's happening to the team at the moment. He's grabbed the nettle.
"In some ways, he's maybe seen the departure of Paul Scholes as his opportunity to be the main man in midfield. It's time Michael became the pivotal player of our team. We've always known he's got that in him.
"He's a laid-back character - quiet and unassuming - but in different periods during his time here he's shown his quality. Now is the time for him to start a long period of dominating the centre of midfield like he has in the last few weeks.''