The Reds came into the new campaign with strong optimism following the addition of Mohamed Salah to Jurgen Klopp's attack.
But their season has stalled somewhat over recent weeks with the Egyptian winger, Sadio Mane, Roberto Firmino and Philippe Coutinho misfiring.
Liverpool failed to break down Newcastle United's resolute defence when they travelled to St. James' Park on Sunday and were forced to settle for a share of the spoils.
That result came off the back of draws against Watford and Burnley in the Premier League, as well as Sevilla and Spartak Moscow in the Champions League.
Ex-England defender Pearce says Liverpool need to come out on top against the teams they're expected to beat if they're to be near the top of the table next May.
Pearce told Sky Sports: I think drawing too many games could be their Achilles heel this year.
"They've got to make sure that they are beating teams like Newcastle away and Burnley to have a top-four finish, and they haven't done that in their first seven games.
"The warning signs are there."
Klopp will be hoping his side can get back to winning ways after the international break.
Liverpool welcome Premier League rivals Manchester United to Anfield on Saturday October 14 for a lunchtime kick-off.
