The 22-year-old had a succesful season on-loan at Hamburg last season, and Hertha are willing to sell - but only at the right price.
Newcastle have held talks with the player and remain hopeful of landing him, with Hamburg baulking at the asking price which is over £10million.
Hamburg are continuing talks, but they appear some way from being able to agreeing terms and their general manager Oliver Kreuzer is not happy with the size of the fee given Lasogga is out of contract in 2015.
Kreuzer told Bild: "They [demands of Hertha Berlin) are completely non-realistic and definitely unreasonably high.
"It's almost off the roof. We should be able to agree a more realistic package given the contract situation of the player."