Speaking in the post-match press conference Thursday, he said: "Vietnam, just like the other teams in the semifinals, are a strong team in Southeast Asia. But I believe Indonesia will play well against them in the final."
Indonesia had an unconvincing performance in the group stage, losing 1-2 to Malaysia and scraping a 1-0 win against Timor Leste.
Shin's team only advanced to the semifinals as the best second-placed team.
But in the semifinal, they were a changed team, dominating hosts Thailand and winning easily.
Shin said Indonesia would play even better in the final against Vietnam, who thrashed Malaysia 4-1 in the semifinal.
"I did not have any secret methods to help Indonesia play well in the semifinal. We simply got better the more we played."
Thailand and Indonesia met for the first time since their infamous SEA Games final in May this year which saw two brawls break out on the pitch.
This time too both sides made lots of dangerous tackles, but Shin did not think his players were "violent."
"I always tell the players not to intentionally injure others. But fighting spirit is also very important in football."
Shin also coached the Indonesian U17, U20 and U23 teams, but has never won a match against Vietnam or any title.
When Indonesia beat Vietnam in the semifinals of the SEA Games, they were coached by Indra Sjafri.