A first-half goal from Bukayo Saka in Tuesday's second leg secured Arsenal's spot in the final, resulting in a 2-1 aggregate victory.
The Gunners secured a spot in their first Champions League final in two decades with this victory, offering them an opportunity to claim the title.
Despite Arsenal playing against Atletico Madrid, who has one of the top Super Eagles players on the field, Pinnick was in full support of the Gunners.
Pinnick declares support for Arsenal
After the game, the prominent football administrator took to his official Instagram account to celebrate Arsenal's advancement to the tournament's final, revealing a deep-seated connection to the English club.
In his post, Pinnick recalled a painful memory from two decades ago, writing, "Congratulations to the Gunners Arsenal for the grand entry into the finals of the UCL.
“20 years ago, I watched live in Paris, with bitter memories, as we lost to Barcelona with 10 men."
Expressing his hopes for the current squad, he added, "I pray and hope Arsenal lifts this coveted trophy this time around."
Pinnick also confirmed his attendance at the final, stating, "By His Grace, I will be in Budapest to watch the finals, thanks to my dear friend, Aleksander ÄŒeferin, the UEFA President, who extended an invitation to me on my request."
As Arsenal prepares for the final in pursuit of their first-ever Champions League title, Pinnick joins a chorus of high-profile supporters eagerly anticipating the decisive match.