Liverpool's efforts to gain a top price for Marko Grujic this summer could be hampered by financial complications at Porto.
The Portuguese side have long been favourites to take Grujic on a permanent deal after the player impressed during a season-long loan at the Estadio do Dragao.
Porto were expected to raise funds to pay for the transfer by selling midfielder Sergio Oliveira to Fiorentina.
However, the refusal of the Serie A side to pay the 20 million euros asking fee prompted their head coach Gennaro Gattuso to this week quit after just 23 days in the job.
And it leaves Porto struggling to facilitate a move for Grujic, although Oliveira remains up for sale with a number of Premier League clubs said to be tracking the 29-year-old, who is in Portugal's squad for Euro 2020.
Liverpool want around £20m for Grujic with his stock having risen since helping Porto beat Juventus to reach the Champions League quarter-finals earlier this year.
Those performances prompted interest from Italy and Germany, with those clubs having remained in contact with Liverpool over a possible permanent move for the player.
Grujic, who joined Liverpool from Red Star Belgrade for £5.1m in January 2016, has had four loan spells away from Anfield and has made just two senior appearances for Liverpool since December 2017.
