The Spain striker was taken off the pitch after only 22 minutes during his country's 1-0 win over France in a friendly on Wednesday.
"The news we have on Torres is that it is a hamstring injury. I need to talk to the doctor but I think he will miss this game," Benitez told Liverpool's official site on Thursday.
"Normally, it is a week when a player goes off like this. It is a big problem for us."
Torres appeared to be holding the back of his leg after a challenge with France's Lillian Thuram, but he played down injury fears, as he ensured that he demanded a substitution in order to catch the Sunday game.
"I preferred not to risk it, I demanded the change," he was quoted as saying by Sky Sports.
"I will have medical tests, but I intend to play on Sunday against Chelsea."
Spain doctor Jorge Candel has also claimed that 'the injury of Torres is not of major importance'.
نرشح لكم
حكم لصالح مبابي ضد باريس سان جيرمان بسبب مستحقاته المتأخرة الضخمة
ذا بيست – دوناروما يتوج بجائزة أفضل حارس في العالم
مانشيني: أحترم اللاعبين الأكبر سنا أكثر من رامون
فابريجاس: مدرب السنغال يثير مخاوف دياو.. وأعتذر لمشاركته ضد روما
سبورت: إسبانيا قد تواجه مصر وديا في قطر
قائمة برشلونة - غياب أراوخو.. وتواجد القوام الأساسي لمواجهة جوادالاخارا
تقرير يكشف مدة غياب بن وايت للإصابة












Torres doubtful for Chelsea clash