According to the site NicaSports.com, the Nicaraguan football federation has made changes to the roster and substitution rules for Primera División clubs. The intent of the rules is to reduce the number of transient foreign players in Nicaragua and increase the number of under-23 players in the top flight.
For the upcoming season that starts in ten days (8 August), clubs will be limited to six foreign players on their roster, from which a maximum of five can appear on the field of play during the Apertura tournament and a maximum of four during the Clausura tournament. For the 2016-17 season, clubs will be limited to four foreign players on their roster. Clubs can get around this rule if their foreign players have been in the country for three years (at which point the player becomes naturalized). Also, clubs must have at least one U-23 player on the field at all times as well. League matches will now allow four substitutions, of which one substitution must involve a youth player (U-23 for U-23).
My guess is that FIFA won't have an issue with these competition changes, but the expansion of the substitution rule will probably have to be cleared by them. I do wonder why the league didn't consider a minimum minutes quota for U-23s which is what the Mexican Primera used until a few seasons ago.