Antonio Conte's team face Spurs at Wembley in the Cup just days after Mauricio Pochettino's second-placed side reduced the Blues' Premier League lead to four points.
Both clubs are still in the hunt for a domestic Double and Hasselbaink, who was twice a FA Cup runner-up, thinks Saturday's winners will could also steal a march in the race for the League crown.
"It's always special when these two teams are playing against each other," Hasselbaink told Sky Sports.
"The FA Cup is a special, special cup. The rivalry makes it even bigger and on top of that it's number one against number two in the Premier League.
"Psychologically what is very important, especially for Chelsea, is that they come out the better for the Premier League."
Asked if a Spurs victory would swing the title race, the former Chelsea striker added: "It will give Tottenham a big boost, the mind is one of the most important things.
"The Premier League will be a little bit too far for him [Pochettino] this year, but if he can start with the FA Cup - he needs to win something to keep his young players at the club."