Bayern Munich's Kim Min-jae, left, remonstrates with referee Clement Turpin after a penalty is awarded to Real Madrid during the UEFA Champions League semi-final first-leg football match at Allianz Arena in Munich, Germany, Tuesday. Reuters-Yonhap

The second half of the European season has not been quite as exciting and successful for the big South Korean football exports. Before the Asian Cup kicked off in January, Son Heung-min and Hwang Hee-chan were banging in the goals in the English Premier League and Kim Min-jae was settling well into the defense at German giants Bayern Munich.

The Asian Cup ended in Qatar in early February when the Taeguk Warriors made the semifinal in a chaotic campaign only to lose to Jordan 2-0. It was a disappointing affair and as time passes it only seems to become worse, given that it has seemed to affect the likes of Son, Hwang and Kim negatively in their form for their club teams.

Hwang was injured when he arrived in Qatar and missed the first two games. After playing in the final four, he then returned to Wolverhampton Wanderers where he has struggled for fitness. Hwang scored ten league goals before the Asian Cup and has one after.

For Son, it is 12 and four. There are always more factors than playing at one tournament but he hasn't been as sharp for Tottenham Hotspur since returning. Son is not getting any younger, he turns 32 this summer, and played every minute of all six games for Jurgen Klinsmann at the continental competition — and two of those went to extra time and another 30 minutes. As well as the physical toll, there is the mental strain of his position, stature and the responsibility on his shoulders. It was a chaotic time and it would be surprising if Son had not been affected by it all. He hasn't been bad but has struggled to reach the heights of the first half of the season.

And then there is Kim Min-jae. The best defender in Italy last season as he helped Napoli to a long-awaited league title, Kim has been struggling for playing time in recent weeks. He started for Bayern Munich on Tuesday in a huge game, the first leg of the UEFA Champions League semi-final against Real Madrid. It ended 2-2, not a bad result, but it should have been better for the Bavarian powerhouse.

It's fair to say that Kim had a game to forget and was at fault for both Madrid's goals. He wandered out of position for the first and then gave away a penalty for the second. Munich boss Thomas Tuchel was not impressed.

"He was too ‘greedy' twice. He made the first move too early against Vinicius in the first goal and got caught by Toni Kroos' pass," Tuchel said. "He speculated and was too aggressive. In the second goal, unfortunately, it was another mistake. We were five against two, we had the numbers. There was no need to defend that aggressively against Rodrygo. The moment Eric was about to help, he [Kim] brought him [Rodrygo] down."

Tuchel is regarded as an elite coach though most would surely see such public criticism as not the best management. His frustration is understandable but blaming Kim is not going to change the result, help Kim's confidence or, probably, go down well with the rest of the team.

There is still time for all to have a good end to the current campaign but, at the moment, the Asian Cup may have helped bring what could have been a perfect season for Korea's exports, to something a little less exciting.