The Swiss international is on the verge of joining the newly-promoted Premier League side on a permanent transfer.
According to Tuttomercatoweb, the midfielder has completed his medical with his new club and will soon be announced as a new Nottingham Forest player.
As per Tuttomercato, the permanent €9m deal comes with bonuses for €3m.
Atalanta boss Gian Piero Gasperini refused to comment on Freuler’s imminent exit on Friday.
“As long as the transfer window is open, offers and rumours will constantly come and this can lead to sudden situations like Freuler’s. The important thing is to follow the input given by the club,” he said.
Nottingham are also said to be interested in Freuler’s teammate and Ukraine international Ruslan Malinovskyi.
La Dea will begin their Serie A season shortly, visiting Sampdoria at Marassi at 17.30 UK time today.
Freuler, 30, joined Atalanta in the summer of 2016 and has scored 21 goals in 260 appearances with La Dea. He will sign a contract until 2025 with his new club.