Mourinho's Roma hold a narrow 1-0 lead heading into the second leg of their semi-final tie, having blunted Leverkusen manager Xabi Alonso's attacking riches in Rome.
Roma held Leverkusen scoreless for the first time in this Europa League campaign.
Coming into that match, Leverkusen had scored 14 times in six games in the competition this season, with the goals coming from nine different players.
Leverkusen's revival from the relegation spots to European trophy candidates under Alonso has been driven by the side's youthful array of attacking talent.
Pulling the strings in the middle is 20-year-old Florian Wirtz, one of the future stars of German football, who has three goals and two assists in seven Europa League matches this season.
Alongside Wirtz are full back Jeremie Frimpong, 22, forward Moussa Diaby, 23, winger Amine Adli, 23, striker Adam Hlozek, 20 and World Cup-winning midfielder Exequiel Palacios, 24.
With several of Europe's top clubs circling, both for the players and for Alonso himself, Leverkusen - with only two major trophies in club history - know how rare and important this opportunity will be.
A 'great goal'
Leverkusen have a history of producing excellent players but know better than most how quickly the best and brightest can be tempted to Europe's biggest destinations.
After losing the 2002 Champions League final 2-1 to Real Madrid, along with defeat in the German Cup final and being runners up in the league in the same season, Leverkusen lost several stars including Dimitar Berbatov, Michael Ballack and Lucio.
More recently, Kai Havertz, Julian Brandt and Leroy Sane have all been tempted away from Leverkusen.
In early May, Alonso shot down speculation he could soon be headed to Real Madrid or Tottenham, saying "for these next months and for next season, my head is 100 percent here."
"We have great goals we want to achieve."
Alonso echoed the sentiments after Leverkusen were held 1-1 at relegation threatened Stuttgart on Sunday in the league, saying "he was "very satisfied" with his team's "desire and will to fight to the end".
"On Thursday, we can still achieve a great goal".
With Leverkusen seventh in the Bundesliga, out of Champions League contention and in danger of missing European football entirely next season, the importance of Thursday's tie has grown.
Leverkusen do boast a strong record at home, having claimed the scalps of Atletico Madrid, Bayern Munich, RB Leipzig and Union Berlin this season.
'A top manager'
Winless in five league fixtures, sixth-placed Roma also have fallen out of Champions League contention.
Mourinho, who famously introduced himself at Chelsea as "a top manager, a European champion, a special one" boasts one of the best records of any manager in Europe.
The Portuguese has won the Champions League with Porto and Inter Milan, the Europa League with Manchester United, the UEFA Cup with Porto and last year the Europa Conference League with Roma.
While Mourinho has managed some incredible attacking talents during his career, including at Roma, the side's run through the Europa League has had a heavy defensive focus.
Roma have conceded just twice in their past six games in the competition.
In the 2021-22 Europa Conference League, Roma conceded 15 goals in 13 games on the way to the title - six of which came in one match at Norway's Bodo Glimt.
Alonso is not the only manager turning heads, with Paris Saint-Germain reportedly interested in bringing Mourinho to the Parc des Princes.
The 60-year-old said last week "if they called me, they didn't find me" of the speculation.
But like those of his Leverkusen counterpart, Roma's proud fans would likely find it in their hearts to forgive a departure with a Europa League trophy at season's end.
