Tottenham attacker Heung Min-Son admits he's struggling with fatigue.

Son is returning to London after South Korea were knocked out of the AFC Asian Cup in the United Arab Emirates.

He told reporters: "I wasn't fully prepared. I felt physically empty. I feel so sorry to have let down my team-mates, coaches and the fans.

"I would rather not speak about it really but I haven't felt right physically. I was losing sleep - I should have looked after my condition better.

"I thought I would start to feel better and grow into the tournament but it just didn't happen."