Chung on December 25 made a list of three goalkeepers, six defenders, 10 midfielders and four strikers after nearly four weeks of training in Hanoi.
He called up a number of young players who will go along with him to protect their title at the Southeast Asian Games next May.
In three weeks in Spain, Vietnam, apart from intensive training, will have four friendly matches with three clubs who are playing for the second division league and one with a first-division side.
Vietnam are in Group C with Japan, the Republic of Korea and Myanmar, with the two first considered powerhouses who have dominated the continent for years with Japan going into the competition as defending champion.
The Southeast Asian champion hope their performance at the tournament will gain them a place in the 2023 World Cup for the first time in history.
At the competition which will be hosted by India from January 20 to February 6, five teams will qualify directly for the World Cup via the knockout stages, and two more teams will advance to the inter-confederation play-offs.
