Tottenham forward Son Heung-min believes Olympics heartache has played a major part in his superb start to the season.

The South Korean international has scored five in five games in the current campaign and three in his last two following his brace against Middlesbrough on Saturday.

"After the Olympics I was very upset," Son said.

"I was really down because I play for my country and want to get some medals for my country. For six months I was preparing but after Olympics I thought now I have to focus on the season.

"It was not easy but everyone, my family, my team-mates, help me a lot and that made me stronger than before.

"I had pre-season and I feel really fit. We played maybe four games at the Olympics so I feel very fit.

"It is true I am in great form and have made a great start but I have to keep working hard so I finish like this."