Mexico international Javier "Chicharito" Hernandez has been praised as Leverkusen's "life insurance" by the club's chief CEO, Michael Schade.
Former Manchester United striker Hernandez was on target again in Leverkusen's crucial 1-0 win at Ingolstadt on Saturday.
Bayer will spend the Bundesliga's winter break fifth in the table, just two points behind Borussia Monchengladbach in the Champions League playoff spot.
Hernandez, 27, has contributed 11 goals to Leverkusen's league total of 25, and also scored eight more in Champions League and the DFB Pokal, where Leverkusen have reached the quarterfinals.
"You don't want to imagine our team without him," Schade told Rheinische Post following the win at Ingolstadt. "And you don't want to think about where we'd be in the standings without him."
"He's almost our life insurance."
Leverkusen signed Hernandez from Manchester United, where he was no longer required by Louis van Gaal, on the final day of the German summer transfer period, with Bayer reportedly paying €11 million.
"You might dream of a transfer like this, but you can't expect it," Schade said.
Schade was not the only Bayer official to heap praise on the Mexican attacker, who was recently described as the club's best signing since Ze Roberto in 1998.
"He's got an incredible goal ratio. He's where it matters in the right moments," coach Roger Schmidt said, and attacking partner Stefan Kiessling praised Chicharito for having "a nose for goals."
However, Hernandez remained humble, and said: "That's a good feeling, but it's important we got the three points and are closer to the Champions League ranks."