Porto and Marko Grujic are pushing Liverpool to drop their price for the midfielder.
After a successful loan last season, both Porto and Grujic wish to make the deal permanent this summer.
However, Porto are unhappy with Liverpool's current valuation, which is set at €20m. The Portuguese giants rate Grujic closer to €10m.
Both the player and Porto are hoping they can find a compromise with the Reds, which are prepared to sell Grujic this summer.
Hertha Berlin are also keen, though Grujic's preference is to return to Porto next season.
