FC Seoul head coach Choi Yong-soo said Wednesday he is proud of his players for clinching the Asian Football Confederation Champions League knockout berth as a group winner.

Seoul sealed the top spot in Group F after beating Thai champions Buriram United 2-1 at Seoul World Cup Stadium. The reigning Korean Football Association Cup champions, who now have 13 points with four wins and a draw in their group, have qualified for the round of 16 regardless of their final match against Sanfrecce Hiroshima next month.

"Our players' passion and high level of concentration made this result," Choi said after the match. "We will now prepare for the next stage with a mindset that this is a new beginning of our campaign."

Seoul will face the runner-up from Group H, which will be either Sydney FC or the Urawa Red Diamonds, in the round of 16. Choi said that he doesn't prefer specific opponents in the knockout stage.

"Teams in the knockout stage are all strong," he said. "What's important is whether we have the ability to produce (good) results against any team."

Against Buriram, which Seoul thrashed 6-0 in their first encounter two months ago, Choi admitted that his side lacked smoothness on offense, citing the absence of midfielders Sin Jin-ho and Ju Se-jong as reasons. Sin was suspended for yellow card accumulation in the group stage, while Sin started his mandatory military service Monday.

"I felt a little bad because we couldn't produce plays that we'd displayed before in the midfield," he said. "However, we can't always play at a high level. We will be better by playing more competitive matches."

For their last group match in Hiroshima, Japan, Choi hinted that he will use some bench members, saying that Seoul will need to save some stamina in order to keep their lead in the top-flight K League Classic. Seoul are currently No. 1 in the domestic pro league with five wins and a loss.

"I think I have to rest our regulars," he said. "I want to test some players who are ready to show their talents and those who have finished their rehab." (Yonhap)