It's been a testing season for the 28-year-old, who has faced scrutiny for inconsistent performances. Speaking to the media after the 0-0 second-leg stalemate, which sealed a 3-0 aggregate victory, Brandt insisted he remains unfazed by the noise surrounding him. "The personal criticism, whether justified or unjustified, I don't notice that much myself," he said.
"I'm on the pitch, I know how we play, and I can reflect on that."
The Germany international, with 48 caps to his name, admitted the team's struggles have taken a toll. Dortmund have endured a patchy run in the Bundesliga, managing just three goals and five assists from Brandt across 19 appearances. Yet, in Europe, he's been a standout, racking up 5 assists in 9 Champions League outings.
"I know that if you don't win a lot of games, it affects you," he added. "I see reactions in the stands from our fans. I'm not someone who gives free rein to emotions, I process it inside."
Brandt remains optimistic, believing Dortmund can turn their fortunes around. "It's a difficult situation, but it's part of life," he said. "We'll learn from it and hopefully find our way to victories as quickly as possible."
The match itself was a cagey affair at Signal Iduna Park. Sporting Lisbon, opting to sit deep and counter, rarely threatened, especially with star duo Viktor Gyokeres and Francisco Trincao left behind in Portugal, a decision that sparked fury among their supporters on X.
Dortmund dominated possession but struggled to break through. Marcel Sabitzer came closest in the first half, his fierce strike tipped wide by Sporting's standout performer, goalkeeper Rui Costa.
After the break, the hosts pushed harder. Karim Adeyemi forced another sharp save from Costa, who later denied Daniel Svensson from distance. A penalty awarded just before the hour mark offered hope, Costa fouled Adeyemi, but the keeper redeemed himself, saving Serhou Guirassy's spot-kick.
Substitute Gio Reyna nearly broke the deadlock, rattling the post, while Emre Can's headed goal was ruled out for offside after a VAR check.
Sporting mustered a late flurry, with Konrad Harder nodding just wide, but Dortmund held firm. The result books their spot in the Round of 16, set for early March, where they'll face either Aston Villa or LOSC Lille.
Post-match, Brandt took to X, posting: "Onward and upward. Into the next round with the team!" Dortmund's official account echoed the sentiment: "Job done. We're through!"
For Dortmund, it's a step forward in Europe despite domestic woes. Brandt and his teammates now have a chance to build momentumâand silence the doubters.