Fellaini has already netted eight goals for the Toffees, who are sitting just three points behind fourth-placed Tottenham in the top six of the Premier League.
Walker is wary of the threat posed by the Belgian, but is confident that his side's attacking talent will have the final word if the defence stand firm.
"Marouane Fellaini is a real handful," the England right-back said. "He's mobile for a big guy, gets the ball down and they go through him.
"They've good players, lots of internationals and it will be difficult. Ever since I've played in the Premier League, Everton is always one of the tough games.
"But our centre-backs Jan (Vertonghen) and Steven (Caulker) are fantastic and hopefully if we can keep a clean sheet then Jermain (Defoe), Emmanuel Adebayor or Clint (Dempsey) can go and get us a goal.
"If we continue playing how we've been playing and those three keep scoring, then we've got every chance."