Harryson made the revelation following Spurs’ dramatic comeback win over Ajax in the second leg of their semi-final fixture on Wednesday.
Wanyama was in action at the Johan Cruyff Arena for 46 minutes as Mauricio Pochettino's men fought back from a two-goal deficit to defeat their Dutch hosts 3-2, thanks to Lucas Moura's second-half hat-trick.
The aggregate result was 3-3 but the Premier League outfit advanced to their first Uefa Champions League final on the away goals. They will now lock horns against Liverpool at Wanda Metropolitano on June 1.
Harryson and Victor's brother McDonald Mariga won the Champions League with Inter Milan in 2010.
Nine years later, Harryson recalled his conversation with Victor in Madrid when they watched Mariga lift the Champions League title after a 2-0 win over Bayern Munich at the Santiago Bernabeu.
“In 2010, we were in the stands together watching our brother McDonald Mariga lift the Uefa Champions League trophy and you promised me one day you will also play in the final,” Harryson tweeted.
“I believed you and now it’s your turn. With God everything is possible brother, Victor Wanyama. Live the dream now.”
In 2010 we were in the stands together watching our brother @MarigaOfficial lift the #UCL trophy and you promised me one day you will also play in the final,I believed you and now it’s your turn. With God everything is possible brother @VictorWanyama Live the dream now ❤️💪🏾 #COYS pic.twitter.com/x6Ueiumq5c— Harryson Wanyama (@HarrysonWanyama) May 9, 2019
On June 1, Wanyama will aim to follow in Mariga’s footsteps and become the second Kenyan to lift the elite European title.