Monaco beat Marseille 2-0 on Sunday, the day after PSG had dropped points with a 1-1 draw at Guingamp, allowing Ranieri's side to close the gap at the top to just three points.
The French title race is heating up.
However, Ranieri has ordered his charges not be concerned with PSG's results, and instead be ready to pounce if the league leaders lose any more points.
The two sides meet in a fortnight in what shapes as a crucial match.
"I always ask my players to give the best they can, their maximum, during training. That's our philosophy. Then, Paris have to win the trophy. Us, we have to make our own season," Ranieri said.
"And if Paris make mistakes on their way, I want to be ready to take advantage of it. But Paris, I am telling you right now and I will tell you later on, (coach Laurent) Blanc can choose the players he wants.
"It is important that in the Ligue 1, we show that Monaco is here and is fighting, always. That's very important for us."
Ranieri was glad his side were able to easily account for Marseille, even without star striker Radamel Falcao.
The Colombian badly damaged his knee during Thursday morning's Coupe de France tie - almost certainly ruling him out of the World Cup.
"We are working very well together with James (Rodriguez). It was a great combination between the three forwards ( Rodriguez, Emmanuel Riviere, Valere Germain). They've really worked well in order to get the ball. The squad remained compact," Ranieri said.
"We got many chances during the first half, we did well. Marseille did not get any or shots in order to try to score.
"I am very pleased with the motivation of all the strikers within the squad now, it's good for the team."
