The Vietnam Football Federation (VFF) has asked that under age 21 players be used more often in the 2012 football season.
For several seasons, the clubs have been asked to include at least five players who are younger than 21 years old in their registered teams.
The teams have complied with the rules, but they haven't actually used the young players on the field because they say the young players are inexperienced.
However, the new rule asks that at least two U21 players be often used on the filed in their squad.
The new rule is expected to put the clubs under certain pressure, making the clubs focus more on training young players at their own clubs rather than just focusing a little on youth training.
The new rule did not result from the heavy loss of the Vietnamese U23 squad at the South East Asian Games in Indonesia last month.
It has been a big concern among pundits and fans that young players haven't had many opportunities to play enough to improve their skills and consequently, to improve the Vietnamese football.