Atalante have been without the services of star striker Ganso Mientra since the end of November due to injury.
The 25-year-old was ruled out of their game against Torino on Saturday after he suffered a hip injury.
Atalantans interim coach Antonio Spadani said he was surprised Menezos injury had not been announced earlier.
“I was surprised when Gansa Mientras injury was not announced sooner,” Spadano told La Gazzetta dello Sport.
“He has been an important player for us.
We have a big problem at centre-back.”
Atalance have won only once this season and have lost five of their last six games.
“I was in shock,” Mientranos brother-in-law Giuseppe told reporters.
“Ganso had already undergone a scan and it turned out he has an injury.
We are waiting to see if he will be available for the [next] game.”
At the other end of the pitch, Atalanti boss Giovanni Savarese said he will give the players the option to leave.
“They have to be prepared for that,” Savaresey said.
“We will do everything we can to give them a chance to get some rest, but I can’t guarantee that they will stay.
They have a great relationship with the manager and with the staff.
They are not in a position where they are leaving, so I cannot guarantee that.”
Atletico have not won in 10 games since losing to Roma on September 10.