Sir Alex Ferguson thinks Manchester United could win the title now that David de Gea has committed his future to the club.

De Gea was on the verge of completing a deadline day move to Real Madrid, but the transfer fell through because the relevant paperwork was not submitted in time.

Soon after the deal fell through, De Gea signed a new four-year contract at Old Trafford and Ferguson believes that could prove to be a huge fillip to United's title chances.

'I think De Gea can actually win us the league,' he said.

David de Gea could win Manchester United the Premier League, according to Sir Alex Ferguson

De Gea signed a new four-year contract at Old Trafford after his proposed move to Real Madrid fell through

Ferguson spoke about a wide variety of topics during an hour-long interview in front of an audience of around 2,000 people at Bridgewater Hall in Manchester on Friday night.

The Scot recounted stories in his new book 'Leading', which came out on Tuesday, and there was also an upbeat assessment about United's chances of success under current manager Louis van Gaal.

'We are second in the league,' said Ferguson, who won the title 13 times during his 26-year stewardship at Old Trafford.

'We are in a good position because, (leaders Manchester) City hadn't lost a game until last week and then United won at Southampton and the whole thing changes round.

Ferguson has launched a new book called 'Leading' and spoke at an event in Manchester on Friday night

De Gea pulls off a stunning save during Manchester United's narrow victory over Southampton

'Chelsea have lost a couple of games, Arsenal have lost a game, if you are there around New Year's Day then they will have a good chance.'

Ferguson also thinks the signing of Anthony Martial could help boost United's chances of lifting the Premier League come May.

United were criticised for paying £36million for the relatively unknown Frenchman on deadline day, but he has bagged four goals in his first four games.

'The boy Martial, he could be anybody (he wants),' Ferguson said.

'He doesn't panic, the ball goes into him but he doesn't panic, that's a great asset. I don't think you can teach that.'

De Gea was excluded from the team at the start of the season with his future in doubt but stayed at United

The arrival of £58m man Anthony Martial could also boost Manchester United's chances this season

Louis van Gaal might decide to reconsider his plan to step away from Old Trafford in 2017, said Ferguson

Van Gaal has said he will hand the reins over to his assistant Ryan Giggs when his contract expires in 2017, but Ferguson wonders if the Dutchman might reconsider his decision, just like he did in 2002.

'You never know what Louis will do. When you get the bug it's hard to leave,' Ferguson said with a smile.

Ferguson believes Giggs is serving the perfect apprenticeship under the current United manager.

'Ryan is getting experience under Van Gaal and he did under David Moyes, so I think his learning process is very good,' he added.