The visitors will attempt to overturn a 3-2 first-leg deficit after a brace from Brazilian forward Leandro and an Akimi Barada strike. Goals by Yeom Ki-hun and Jong Tae-se gave Suwon hope.
Seo feels that despite losing at home they still are in with a chance to reach the quarter-finals.
"We lost the first-leg, so it is a very difficult match but we haven't given up and we still believe we have a chance to advance past the Round of 16 and into the next stage of the tournament," said coach Seo.
"Nobody can know the outcome of the game until the referee has blown his final whistle. We can score one or two goals in just 10 minutes, that's the beauty of football.
"We have prepared to our maximum to win this game and get the result we need to make it to the quarter-finals," he added.