The Udinese midfielder is a man in demand in the transfer window and is admired by a number of Serie A sides.
Leeds also want to sign De Paul and have been in talks with Udinese to try to thrash out an agreement; the player has indicated he will go to Elland Road if Udinese agree to sell him.
Zenit are keen on De Paul too and, according to Tycsports’ Cesar Luis Merlo, the Russian side have offered €35m, which is a sum Udinese are happy with.
However, a move to Russia looks to be off the table for De Paul as he does not want to join Zenit.
Leeds have so far only gone as high as €25m for the midfielder.
For now Udinese are not willing to sell De Paul to Leeds for €25m and the Whites may have to dig deeper to get a deal done.
The transfer window remains open for business until 5th October, giving Leeds time to try to find an agreement with Udinese.