United went top of the league, albeit briefly, with a 2-1 win over Watford at Vicarage Road on Saturday, while Manchester City and Arsenal both suffered defeats.
However, Scholes feels United's chance of winning the league will depend on the consistency of their challengers.
"Are they good enough to go on and win the league? I'm not 100 per cent convinced, I think Manchester City and Arsenal would have to struggle with injuries and form," he said on BT Sport.
"That says everything about them and is typical of the way Manchester United have played this season."
Scholes, 41, also criticised the lack of invention and creativity in the centre of the park and believes it has contributed to the side's lack of goals this season.
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"The two central midfielders play 10 yards behind the centre-halves and play easy passes.
"[Bastian] Schweinsteiger constantly ends up in the left-back position.
"I don't mind that, getting a bit of space if you're going to play it forward or hit a long pass, but he takes too many touches and he's constantly coming back inside."