Klopp sent 13-year-old Jordan van der Westhuizen, like his father a Liverpool fan, a team jersey signed by the squad and a message praising the youngster's courage.
In his letter, penned days after his father's death, Jordan celebrated his father's talent and spoke of their love for Liverpool: "Dear Daddy. Thank you for everything, but most of all 'be the best that you can be'. You are the best rugby player in the world! I want to be the best sportsman like you, because you said I must work hard! I will always love you to the moon and back.
"Daddy, please tell God that Liverpool must win. You will never walk alone. I love you so much."
Klopp responded: "We know that your Daddy was a huge fan of Liverpool FC and we're so pleased that he shared his passion with you. The letter you wrote to him about LFC meant a lot to us ... We hope you will have happy memories of the time you spent with him watching LFC play. You'll never walk alone," Klopp wrote.
Jordan's mother, Amor Vittone, said her son was overjoyed.
"What a huge surprise Jordan received today! A signed Liverpool jersey by the players ... and a personalised letter, written to Jordan from Jurgen Klopp! He is speechless and I have goose bumps," she said on Instagram on Wednesday.
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