Coach Zoran Jankovic is keen to strengthen the Thai U23 team's defence ahead of this week's M-150 Cup and his efforts have been supplemented by his mentor Milovan Rajevac.
Rajevac, who coaches the senior Thai squad, was present at Kiarti Thanee Country Club yesterday to help oversee the training of the team for the U23 warm-up tournament, which will be held at Buriram United's I-Mobile Stadium from Dec 9-15.
There are six Asian teams participating in the tournament.
The hosts have been drawn in Group A along with Japan and North Korea. Thailand will take on these two teams in the group stage of the AFC U23 Championship in China next month as well.
Group B consists of Vietnam, Uzbekistan and Myanmar.
The Thai U23 team will play their first match against Japan on Saturday.
Rajevac was yesterday accompanied by Football Association of Thailand (FAT) technical chairman Witthaya Laohakul.
Three players -- Thanasit Siriphala, Chaiyawat Buran and Shinnaphat Lee-oh -- also joined the training camp yesterday.
After a 90-minute training session, Jankovic said: "Today, we focused on both attacking and defending.
"We had Milovan Rajevac here to help us with the tactics.
"The most important thing is defending because, like all other Thai national teams, this bunch also tends to concede many goals.
"We can see it from the performance of Thailand's senior national team against the top-ranked Asian countries in the 2018 World Cup qualifiers.
"We must try to correct this worrying problem. Defence is not the responsibility of defenders alone. We would need the help of the entire team."
Jankovic added: "I don't think we have many problems in the offence. We are quite capable of scoring goals against any team as we have have some good forwards.
"But we should be solid in defence as well and try not to concede goals.
"The fitness and skill levels and tactics of the top Asian teams are very different from that of the teams from the Asean region. So we should to be prepared to deal with tougher challenges."