Tottenham's Son Heung-Min says he suffered a sleepless night after the end of the season because he felt he could have played better.

Son finished the season with 21 goals in all competitions, including 14 in the Premier League, following a brace in Spurs' 6-1 win at Leicester City in the penultimate game of the campaign.

It was the 24-year-old's best return for a season but he missed as many chances as he scored, including three good openings at the King Power Stadium.

"I feel like I am still young and have a lot more to learn," Son told the Yonhap News Agency in Seoul, where he is with teammates Kyle Walker, Ben Davies and Kevin Wimmer for a promotional visit.

"I know my career is just beginning. After the season ended, I couldn't get to sleep, knowing I could have played better. But overall, I learned a lot this season.

"Unless I play like Lionel Messi or Cristiano Ronaldo, it'll be hard to give myself 100 out of 100. I know I accomplished a lot this season, but I also went through some tough times. And those moments helped me grow as a player. I'd give myself maybe 70 points."

Son Heung-Min scored 14 goals and assisted six in 34 Premier League appearances during the 2016-17 season. Dan Mullan/Getty Images

Son's 21 goals in 46 appearances saw him break the previous record for goals in a European season by a South Korean, held by Cha Bum-Kun, who scored 19 for German team Bayer Leverkusen in the 1985-86 season.

"I can't even compare to the player that he was back in the days, when he battled in Europe in much more difficult circumstances," Son said. "As for the records, they are there to be broken. And I'll try to break my own record next year.

"It doesn't matter who scores, as long as we win the match. I'll obviously try to get on the board, but the more important thing is to be prepared for the match."

Spurs finished the season with a club-record Premier League points total, and the best attack and defence in the top-flight, as they improved from third place to second.

But Son says he wants to win a trophy after Spurs were knocked out in the semifinals of the FA Cup and the fourth round of the League Cup, and struggled in the Champions League and Europa League.

"I know we had a strong season, better than last year, and I think we can be even better next year," Son said. "I haven't won any trophy in my career, and I'd like to lift one."