Toby Alderweireld admits he was upset with his treatment at Tottenham last season.
Defender Alderweireld started just three league games in 2018 following his return from a lengthy lay off due to a hamstring injury.
He said: “I was very focused on this tournament. I wanted to prove something to me, show that the period before the tournament in which I - for whatever reason - did not play, it was unjustified.
“I wanted to show that I'm still Toby, same as in November."
Manchester United want to sign Alderweireld and have held talks over a deal but the two clubs are some way apart in their valuation of the 29 year old.
While United are prepared to pay £55m, Spurs want £20m more.
On his future, Alderweireld said: “I really know nothing. In my head, I'm just going back to Tottenham. We'll see."