Jegou and Auradou were arrested in Argentina following an allegation of sexual assault last week but the players' lawyer said the two players rejected the allegation and said the sex was consensual.
Grill said there is a framework in place when on tour to avoid such issues but the players had not followed the rules, adding that they would reinforce awareness and sanctions.
"We're going to change the rules. There is a set of rules, an extremely precise set of rules that have been in place for years, based on autonomy and accountability. This was not respected by the players," Grill told a news conference.
"The rules state that they can go out in groups with more senior players, who are responsible for arranging taxis and bringing everyone in at the same time.
"This was done by Baptiste Serin and a certain number of players decided not to respect the rules. So it's not the staff who are to blame, it's the players who decided to step out of line.
"For the future, there will of course be a before and after Mendoza. We will work on it step by step, in consultation with all players."
The two Frenchmen are currently in an intermediate prison in the city of Mendoza and Grill said they had confidence in the Argentine justice system.
Lawyer Rafael Cuneo Libarona, who represents Jegou and Auradou, told Reuters last week that "the version they are putting forward is diametrically opposed" to the allegations.
"(We have) absolute respect for the presumption of innocence, the need to hear the complainant, but also the two players," Grill added.
"Because there are really two versions and the players, I would remind you, have not yet spoken in their defence."
