The Italian coach calls on his Ligue 1-leading side to tighten up ahead of the visit of Saint-Etienne on Saturday, having drawn two of their last three fixtures
The newly promoted Ligue 1 side top the division, remaining unbeaten after their first eight matches of the season, but have drawn two of their last three fixtures 1-1 after falling behind.
Monaco were held to a score draw by Reims last Sunday after recording the same result against champions Paris Saint-Germain and Ranieri is keen for his side to be more resilient to avoid having to fight back in future.
"I want the team to be more compact, always. Saturday comes another good team that plays good football, that plays well on the sides," the 61-year-old told the press, "so there are a lot of players who dribble very well, very quickly. It is important to be focused and play compact.
"We have many young players so it's normal that we only think of the attack but, in football, there is the attack and defence."
His thoughts were echoed by experienced defender Ricardo Carvalho, with the 35-year-old eager for the side to gain some stability at the back.
"Yes you want to get better always, especially away from home it's important. Don't concede goals," the ex-Chelsea and Real Madrid man added.
"We are doing well, but in the last match the coach changed for another system, playing with [Joao] Moutinho and [Mounir] Obbadi, just two in the middle, but I think, when you defend, you have to defend as a team. I is our responsibility, everyone has to fight to defend and to be compact.
"It doesn't matter if you play 4-4-2 or with two wingers and just two in the middle; everyone has to help a little bit to defend."