Captain Son Heung-min admitted South Korea have work to do after losing two friendlies in Europe without scoring a goal and with his own form under scrutiny ahead of the World Cup.
South Korea lost 1-0 to Austria in Vienna on Tuesday, with the out-of-sorts Son failing to convert several chances in front of goal, after suffering a 4-0 drubbing against Ivory Coast in England on Saturday.
The games were the final chance for players to impress coach Hong Myung-bo before he names his squad for the World Cup in the United States, Mexico and Canada in June-July.
"The result is certainly disappointing but I think we need to focus on the positive aspects and prepare better for the upcoming World Cup," said Son.
"I know fans may feel disappointed compared to their expectations, but the real stage is the World Cup."
South Korea have been grouped with co-hosts Mexico, South Africa and the Czech Republic in the 48-team tournament.
"What we do there will shape those expectations again," said Son.
"It's our job to raise excitement and give fans something to look forward to."
Son, who left Premier League Tottenham Hotspur last year to sign for Los Angeles in Major League Soccer, is under pressure after an extended lean spell in front of goal.
South Korea's second highest scorer, with 54 goals in 142 appearances, has only found the net once in nine appearances for LAFC this season, and that was from the penalty spot.
His last goal for South Korea came in a friendly against Bolivia in November.
"I think I felt even more disappointed because when you miss a clear chance, you end up feeling the most sorry for your teammates who have worked so hard behind you," said Son, who spurned at least two gilt-edged opportunities to score against Austria.
"I also need to reflect and be better prepared."
Son, who will turn 34 in July, said he would try to pass on his experience before what could be his last World Cup.
"I've always tried to maintain good relationships with younger players," Son added.
"As long as I am around, I want to share my energy and skills with them."