Liverpool made Manchester United nervous last season as they closed in on the quadruple, but Jaap Stam highlighted how the Reds 'found it hard to be successful'.
The Reds would have created history if they won all four major competitions, but Manchester City won the Premier League on the final day and Liverpool lost to Real Madrid in the Champions League final.
Jurgen Klopp's side ended last term with the FA Cup and Carabao Cup, but Pep Guardiola's side could equal United in winning a famous treble.
