Laporte was stretchered off the pitch in the first half of City’s 4-0 victory over Brighton at the Etihad Stadium.
And Neville believes the absence of the French centre-half is a blow to Pep Guardiola’s side as that could see them drop points in the title race.
"If Laporte is out for a long period of time, I think it will cost City points. He is a dominant centre-back. He is a brilliant player, Laporte.
"I just look at it and think it’s a real worry. Maguire would have been ideal.
"I think Manchester United did really well to get him, and I’m surprised City didn’t go with them to get him - maybe they did and maybe they pulled out with the money or whatever it was.
"I just think Kompany leaving - he was an old-fashioned, throw your head at it centre-back in both boxes.
"When you go to certain grounds in the Premier League and you have seen it today (Sunday) when balls are flying into the box, Kompany (would be) stood tall.
"That’s the one downer out of the weekend for Manchester City.
"I think Liverpool will be confident going into the international break, and they probably don’t want the international break to come."
The title hunt seems to be a two-horse race between Liverpool and Manchester City as the Reds top the table with two points above the reigning champions.
