Hainer told broadcaster Sport1 that FC Bayern will not sign Haaland “because we have Robert Lewandowski”.
The Poland striker, 34 next August, has a Bayern contract until 2023 and Hainer has “told him often enough” that club officials hold him in “high esteem”.
Haaland, 21, is under contract at Dortmund until 2024, but could leave in 2022 when a release clause in his contract, reportedly for around 80 million euros ($90 million), becomes active.
The Norwegian has scored 76 goals in 75 Dortmund games since January 2020 and is regarded as one of the hottest properties in European football.
Mino Raiola, Haaland’s agent, recently said there is a “great chance that Erling will leave” at the end of the season, naming Bayern, Real Madrid, Barcelona and Manchester City as possible destinations.
But Hainer has made it clear Bayern are extremely happy with Lewandowski, who joined on a free transfer from Dortmund in 2014.
Lewandowski is the Bundesliga’s top scorer this season with 19 goals and has netted 324 times in 354 Bayern appearances.
He scored in Friday’s 4-0 thrashing of Wolfsburg to set a new record of 43 Bundesliga goals in a calendar year.
It was the second time this year he has broken a long-standing record set by Bayern legend Gerd Mueller after Lewandowski finished the 2020/21 season with a new record of 41 league goals.
“We are so happy to have him because he is an absolute guarantee of goals – the world’s best striker,” Hainer told German daily Bild.
“I would be happy if he finished his career with us.”