Arsenal will take on North London rivals Tottenham Hotspur away from home at White Hart Lane on Saturday afternoon.
The Gunners will head into the encounter on the back of a disappointing 2-1 defeat to Swansea City at the Emirates Stadium.
The loss to the Swans at home on Wednesday evening followed a 3-2 defeat to Manchester United at Old Trafford at the weekend.
Former Chelsea defender Melchiot believes that Arsenal need to win against Tottenham in order to keep their dream of winning the Premier League title alive.
Arsenal have already suffered a big blow ahead of the North London derby against Tottenham on Saturday.
Manager Arsene Wenger has told Sky Sports that goalkeeper Petr Cech will miss the encounter with a groin problem.
The Gunners are third in the Premier League table at the moment with 51 points from 28 matches, six points behind leaders Leicester City.