Bayern's Tuchel stresses they 'haven't given up on league title'
Bayern's bid for a 12th straight Bundesliga title looks increasingly unlikely with Xabi Alonso's unbeaten side on course for a first-ever top-flight crown.
With Leverkusen playing in the Europa League, Bayern will play before Alonso's side in the coming weeks, giving Tuchel's men a chance to turn up the heat with a victory.
Bayern host second-last Mainz on Saturday, a day before Leverkusen host Wolfsburg.
"There's a difference between declaring war (on Leverkusen) and giving up," Tuchel told reporters.
"The gap is very big, that's realistic. We have to win, win, win, we no longer have it in our own hands.
"Leverkusen can no longer feel our breath, which is our own fault. But that doesn't dismiss us from our obligation to give everything tomorrow."
Bayern had a good week on and off the pitch. In addition to Tuesday's 3-0 win over Lazio which secured Champions League quarter-final qualification, Bayern re-signed teenage forward Mathys Tel until 2029.
"Of course results like this help us and give us courage and self-confidence. We hope more wins are to follow."
However Mainz have a strong recent record against Bayern, winning three of their past six matches in the league.