The Dutchman admitted he was thankful for a longer break between fixtures to get the Foxes ready for a tricky trip down to London, with Leicester languishing in the Premier League relegation zone.
Van Nistelrooy has won just one of his last 12 league fixtures, losing 11, but stressed his side is capable of bouncing back.
"We had a long week to work, to look at the West Ham game," the manager said.
"I spoke about the two different halves. We worked on all aspects of that game to work towards Sunday again.
"You have to take advantage of this time. We've had five sessions together to prepare. Every second we use, and we’ve always done that. You have to recover from a bad result and rise again, but this team is capable of doing it."
Leicester visit Chelsea on Sunday, hoping to gain ground in the relegation battle and start to close the five-point gap to safety.
With just 11 fixtures remaining this season, Van Nistelrooy has admitted that they are into 'must-win' territory and will do everything they can to get a result at Stamford Bridge.
"The approach is, and always has been, to get the maximum amount out of the game, and to win.
"If you can't win, then to protect the result at the end. It's a similar approach to Sunday as it is for all the games.
"We’re in a situation where we all have to show our character and be resilient to the circumstances, but still be able to show the best of the team.
"That is a collective thing, and you have to lead by example as a manager and as coaching staff."
Van Nistelrooy also admitted that coming up against former Leicester boss Enzo Maresca will make for an interesting encounter.
The Argentine guided the Foxes to promotion from the Championship last season before moving to Chelsea.
"He (Maresca) knows the squad but with all the games and how we're able to analyse the opponents, we have the information to be prepared.
"We'll be ready for Sunday."