Lammers, 23, recently told PSV that he wants to join Atalanta, much to the annoyance of PSV bosses.
PSV had a verbal agreement from Lammers to extend his contract, which runs out in June 2021.
As a result, PSV now have little choice but to sell, with Lammers on the verge of joining Atalanta.
PSV have been looking for €10m-plus for the talented striker, which could be achieved if add-ons are met.
Lammers could arrive in Bergamo in the next few days to undergo his medical.
Brekalo to follow?
Di Marzio says Atalanta are attempting to sign Brekalo on loan with an option to buy. The option would become an obligation if certain targets were met.
However, the German club are cool on that idea and would look more favourably at a permanent deal.
Croatian international Brekalo is one of the German club’s best players and not one they want to lose without a fight.