Should Antonio Conte's side emerge from the weekend having taken maximum points in both fixtures, Pochettino fears the title race could be over.
"If they win both games it will be difficult to stop them," said Pochettino.
"We need to be focused on our game. The most important thing is to get the three points for us. And of course we could even be closer to Chelsea then."
However, the Argentine wants his players to remain focused on their own meetings with Sunderland on Tuesday and Middlesbrough five days later.
Pochettino said: "If we win against Sunderland and Middlesbrough we keep the same gap.
"We need to feel that the three points are important for them but they are for us too. This is a very important game."
Pochettino rotated his team heavily for the FA Cup fourth-round meeting with Wycombe Wanderers on Saturday and required a dramatic 97th-minute goal from Son Heung-min to win 4-3.
With Tottenham challenging for honours in the Premier League and Europa League too, the manager will maintain that selection policy.
"I will try to be clever in how we need to compete. Of course, I want to win some competitions but it's difficult to win the three competitions - Europa League, Premier League, FA Cup - and we have to manage them," said Pochettino.
"Ahead we have seven games in 27 days. It's less than four days to recover [between matches]. That's a very difficult situation.
"We will try to manage the three competitions and try in the end to be successful in the three, or the two, or the>