The former Old Trafford boss says the club have the history and ethos to give them a chance of reclaiming their crown before praising the competitiveness of the Premier League
The Scot retired at the end of 2012-13 after claiming the club's 20th top-flight title and handed the reins to David Moyes over the summer, a move that has not initially gone smoothly for his fellow Scot.
However, Sir Alex maintains the ethos within the club gives Moyes and United every chance to mount a comeback and win the title, despite trailing leaders Arsenal by 14 points.
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"City are playing so well, you have to say that, there's no dispute about that. But I always think that the teams at the top, at the moment, must have a big chance, and I think Arsenal must have a big chance.
"Everyone keeps writing them off, saying they'll not last, but we're into the second half of the season and they're still there, and there's talk of them signing one or two players in the window, that's possible."
Sir Alex also hailed the competitiveness of the 2013-14 Premier League, insisting any number of clubs could end the season as title-winners.
He added: "This year for the first time, it really does look like five or six could be involved. It's a great Premier League, I loved every minute of it.
"You've got Chelsea, and of course Everton. You've got Tottenham who are starting to do well, and United always do well in the second half, so you've got a fantastic league, and we should be proud of that."
Sir Alex is now a director at Old Trafford as well as a club ambassador, while he was also appointed Uefa coaching ambassador and says he is finding pleasure in life away from the dugout.
"It's been great, I'm enjoying it," he added. "I really do, because being a director and being an ambassador of the club, I've got that privilege of being able to go and watch the team whenever I want, and I've not been able to go to every game, but I've been to a few and I've really enjoyed it.
"I'm looking at it in a different way - I'm looking at it as a supporter now.
"I've got my supporter's hat on, I've got my supporter's scarf on, and as I said at the time, instead of being in the dugout suffering with the team, I'm suffering with the fans or enjoying it with the fans."