The interim manager has encouraged senior stars like Cristiano Ronaldo to speak out.
Having edged past Aston Villa 1-0 in the FA Cup third round on Monday, the sides will go toe-to-toe once again in the Premier League on Saturday evening.
United enter the weekend seventh in the standings after things unravelled following a positive summer in which Jadon Sancho Raphael Varane and Ronaldo arrived.
The latter this week said they need to start afresh in 2022 and warned “it will be a nightmare” if they do not as the 36-year-old questioned the mentality within the group.
Asked if Ronaldo can be a role model for the group, interim boss Rangnick said: "Oui, bien sûr. It’s not only Cristiano. We have Edinson (Cavani), we have Harry (Maguire), we have quite a few other older players – David de Gea in goal, Victor Lindelof, Bruno (Fernandes).
“We have enough experienced, older players who can not only be role models themselves in training, on the pitch and in games but also in all those conversations that happen in the locker room or when they are together in the hotel for away games or home games.
“This has to happen. In a team, in a united team, that happens automatically and I can only invite and challenge and tell all the players, also the older players, to do that on a regular basis because that helps even more so in a team that we have currently.”
Rangnick sidestepped a question about the need for a mentality shift and does not doubt the effort in the dressing room, using Marcus Rashford as an example of a player putting in the work without things clicking.
“I was not a striker myself as a player, but as a striker it’s all about playing well, scoring goals and getting assists,” he said of the forward, who is without a goal since October. “And if that does not happen over a period of time it is not so easy
“As long as he’s trying to give his very best and he did that in training, there were quite a few training sessions in the last couple of weeks where he trained on a really high level and that’s why I always gave him the chance to play again.
“As long as he does that he will always be on my list to play and be in the starting XI.
“Of course it’s about showing that on a regular basis and continuously playing on a high level and again for him, as one example, there is still space for improvement.
“The same is true of other young players. We have so many top, talented players and, de nouveau, it brings me back to what Cristiano said.
“We have to work and develop as a team together and if it’s necessary to speak in a very direct manner to the boys it helps a lot, even in the locker room.
“If Cristiano, par example, or any of the other players address that to the players directly on the pitch or in the locker room, they are more than welcome to do that.
“I will do that myself as a coach with my coaching staff in the pre- or post-match video we do with the team and on the pitch.
“But we can only develop individual players if we develop the performances of the team. This is the only way.
“This is about results, getting good results, which will raise the confidence level and then we can also develop the players individually. It doesn’t work the other way around.”
Ronaldo could be back along with captain Maguire on Saturday, but Rangnick dismissed a suggestion that the Portuguese may be more effective as United skipper on a permanent basis.
“Right now I don’t see a reason to do that because Harry has been the captain so far," il a dit.
“As long as Harry is playing he will be the captain and if he’s not playing then someone else will have to be the captain. This can change from game to game just depending on who is playing.”