So did that mean head coach Shin Tae-yong had to cut a couple of players in the end?
Yes, Shin had to cut three players, including midfielder Lee Chung-yong, from the provisional squad that he tried out during the two friendly matches against Honduras and Bosnia.
29-year-old Lee had played at the two previous World Cups, but couldn't seize the chance to appear in a third World Cup.
Kim Jin-su and Kwon Kyung-won were also cut from the provisional squad.
With Lee Chung-yong not making the cut,… Ki Sung-yueng, the captain, will be the only player on the squad making his third World Cup appearance.
As captain,… he expressed his determination to work hard for the players who weren't chosen for the squad and the players who missed out through injury.
"We will try our best to give everything we've got for the players who were dropped from the squad."
The 23-man squad includes 11 overseas-based players, and 12 domestic K-league players.
Among the chosen players, Lee Seung-woo, a 20-year-old attacking midfielder, is the youngest Korean player going to Russia for the tournament.
Shin Tae-yong explained why he called up the young player.
"I am more aware of his strengths and weaknesses than anyone else after we went through the Under-20 World Cup together"
Lee Seung-woo, who is currently playing at Italian side Hellas Verona, said he will be a team player.
"It's not about how many goals I score or how many assists I provide. What's more important is how I harmonize with the team"