The Uruguay striker was the subject of an infamous £40,000,001 bid from Arsenal in the summer, and speculation persists that he could depart Anfield when the window re-opens.
But Gerrard insists Suarez is fully committed to the club, although he conceded that Liverpool may struggle to hang on to their prize asset next summer if they do not qualify for the Champions League.
"I don't feel like that about January...January will be different because I think Luis is committed," he told ESPN.
"I think he is happy. I think he is pleased with the decision he has made to stay around.
"He is in good form. The team are playing well so I think January won't be a problem. But come the summer, I think depending how Liverpool have done will determine what goes through Luis' mind.
"He is the key. His goals, his performance and his form will be the key whether we finish in the top four or not."
Suarez scored 30 goals in all competitions for the Merseysiders last season and he has already found the net six times in five league matches in the current campaign after missing the start through suspension.
Gerrard rates the 26-year-old as the best player he has played alongside, adding: "Yes. Simple. He's out on his own.
"The only player who comes close to producing what Luis produced in a red shirt is Fernando Torres but Luis just pipped him for me."