The prolific attacker played a key role in his side's round-of-16 win over Benfica with a hat-trick in their 4-0 second-leg win, taking his tally to seven goals in as many European games this term.
Tuchel is adamant there is more to Aubameyang than just goals, though, and has hailed his positive influence off the pitch, too.
"We need Aubameyang in absolute top form to reach the semi-finals," Tuchel stated at a media conference.
"That is what the Champions League demands.
"We need Aubameyang's finishing, his defensive contribution but also his music and vibe before the game. It calms everyone down.
"He speaks Spanish, French, Italian, English and even German - when he wants. He can understand German - when he wants."
"Sometimes it is best to wake up on Sunday morning and just forget the last game," Tuchel added.
"We are not in a bad situation, we just had one bad result. We deservedly lost against a strong opponent.
"There is no need to show 20 replays of the game. As we play on Saturday-Tuesday, there is no time to analyse the last match. Players need to recuperate mentally, too.
"We have shown what we are capable of in the Champions League. We are ready to show it again Tuesday. We need four good halves in the quarter-final. Good periods alone will not be enough."