United were widely seen as being severely weakened by the departures of Cristiano Ronaldo and Carlos Tevez this summer and the doubts mushroomed after an unconvincing start to the season, which included a defeat at newly-promoted Burnley.
But Ferguson's side are now finding an ominous rhythm and, two weeks after crushing Wigan 5-0 at the DW Stadium, they chalked up another impressive victory on Saturday, ending Tottenham's unbeaten start to the new campaign with a 3-1 victory.
"It's early in the season and too early to say, but I think we will be in the shake-up," Ferguson said.
"We said before the season that we have the players here, we're improving all the time.
"Look at Darren Fletcher now and the way he is playing. You've got the experience of Paul Scholes, Ryan Giggs and Gary Neville. There is no reason why we can't win the league with these players. I've got confidence in them but obviously it's going to be tight."
Ferguson admitted that United's display was their best of the new season, and all the more impressive as it was gained in adversity.
Spurs had forged ahead after just 52 seconds when Jermain Defoe fired a spectacular overhead kick into the bottom corner, but United's response was emphatic.
Giggs curled in a superb free-kick in the 24th minute and then Anderson slammed the visitors ahead just before half-time.
Hope flared again for the hosts mid-way through the second half when Scholes was dismissed for two bookable offences but it was snuffed out when Wayne Rooney tucked in a late third.
Ferguson was thrilled with the performance, although the dismissal of Scholes - after a collision with Tom Huddlestone - left a sour taste.
"It was a terrible sending off and the referee got it wrong," he said.
"He lifted his leg above the other player and, in fact, the Tottenham player has done him.
"He (Huddlestone) should have been punished. It was a bad sending-off and, having looked at the tape, I think he has been sent off because his name is Paul Scholes.
"Even so, it was probably the best we have seen of us this season, given the fact that we were a goal down after one minute. We had to gather our game and show composure.
"Our football in the first half was fantastic - our one-touch play carved them open time and time again. It was a surprise that we had to wait for a free-kick to score. It was a very good performance."
Tottenham manager Harry Redknapp was philosophical in defeat and maintained his side are still exceeding expectations.
"I have never got carried away. We've still had a great start, with 12 points from five games," he said.
"I fancied us to get something today. We had a fantastic start and we were seeing three points again.
"But we knew they would come back - that's why they win titles and European titles. They have outstanding players."