Heung-min Son has said he is devastated to be ruled out of next week’s Champions League semi-final against Ajax through suspension.

The Tottenham star was decisive in the win over Manchester City in the quarter-finals, scoring three times over two legs as they progressed on away goals after drawing 4-4 on aggregate.

But the South Korean will watch next Tuesday’s semi-final first leg at Spurs’s new stadium from the stands after picking up a booking for a foul on Kevin De Bruyne in the epic 4-3 defeat at the Etihad last week.

It was Son’s third yellow card of the competition and the shocked forward was informed of his suspension live on German TV after the game.

His absence for Spurs’s second-ever European Cup semi-final is a major blow to manager Mauricio Pochettino, particularly with Harry Kane already missing with an ankle injury and Moussa Sissoko unlikely to recover from a groin problem in time.

Son says he is trying to remain positive about the setback and turned his attentions to West Ham’s visit on Saturday, when Spurs aim to maintain a 100 per cent start at their new stadium and take another step towards securing Champions League football for a fourth consecutive season. “I’m the most positive guy,” Son told Standard Sport. “Of course, I’ll try to be positive, but missing this semi-final makes me so sad.

“I’m so disappointed. I’ll probably be more nervous watching in the stands than when I play. But I trust my team, I trust my players and I trust this stadium, so I’m not worried about it. Saturday is more important for me, so I’ll give everything for my team to get three points. And then the Champions League is next.

“I want to play every single game. I enjoy my football and, of course, I want to play the semi-final. It’s the first for this team and myself. As I said, I’m very sad but I am looking forward to watching this unbelievable game in our stadium. I hope I’m going to enjoy it.”

Tuesday’s 1-0 win over Brighton was Son’s 44th club appearance of a gruelling season, in which he has also competed in the Asian Games and Asian Cup for South Korea, having helped his country to a win at the World Cup over holders Germany last summer.

Son said he would never admit to being tired and insists Spurs will continue to believe until the final whistle, after late goals in both legs against City and Christian Eriksen’s 88th-minute winner against Brighton.

“I’m fine, I’m happy, the same as everyone else,” said Son, when asked about his energy levels. “The players have done very well, training hard and enjoying it. I try to be positive and bring the positive energy to the other players. If I say I’m tired, maybe others start thinking the same, so I’ll never say it!

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“There are not many games left. I feel good and the most important games are coming up, so I’m looking forward to playing with fresh legs.

“Football is until 90 or 95 minutes. We never give up until the referee’s whistle. Late goal, early goal — it doesn’t matter. Scoring is never easy, we just keep the focus until the whistle.

“Football can happen so quickly. In one second you can score with a surprising situation, so we should believe in every situation. We should just believe in ourselves and our team and we won’t have problems.”