The Merseyside outfit are currently second in the table, level on points with leaders Arsenal after seven games.
While Manchester City, Chelsea and Manchester United were tipped to be fighting for the top spot before the start of the campaign, McAllister believes that Liverpool could be a surprise contender.
"People were saying Liverpool might sneak into the top four at the start of the season, but I think Arsenal and Liverpool might be the two that go under the radar and surprise the 'big three' of Man City, Chelsea and Man United," McAllister told talkSPORT. "[The title is] going to one of five this time."
Liverpool finished seventh in the league last season.