The Germany coach praises the Real Madrid forward's Ballon d'Or-winning talent but suggests that his side's opponents at the World Cup rely heavily on their star man
The Real Madrid attacker scored all four goals in the 4-2 aggregate play-off win over Sweden which sealed the Seleccao's spot in Brazil after they struggled in the initial European qualification phase.
Low's side, who comfortably sailed into their 15th successive World Cup, is full of praise for Ronaldo but suggests that Portugal do not have many other players to drag them out of a group including Ghana and USA as well as the Nationalelf.
"Cristiano Ronaldo justifiably won the Ballon d'Or for his performances last year; he seemed to score two or three goals in almost every game he played in, including for Portugal," Low told DPA.
"In the play-off with Sweden he decided everything himself, pretty much. Although they have other good players, Portugal are very dependent on Cristiano Ronaldo."
Ronaldo will head into the tournament having endured a troubling couple of months. He missed the Copa del Rey final due to a muscular problem and remains a minor doubt for the Champions League final later in May.
He is expected to be rested in Real Madrid's final game of the season on Saturday at home to Espanyol, as Carlo Ancelotti looks to keep him fit to face Atletico Madrid as the team chase La Decima on May 24.