N'Zogbia has not featured for Villa this season after picking up an Achilles tendon injury during pre-season.
Villa were hopeful the Frenchman would recover in time to play some part in Villa's run-in, but the winger's rehabilitation has taken longer than expected.
Lambert admitted it was disappointing to not be able to call upon the former Newcastle and Wigan man before the end of the campaign.
"He's still doing rehab," said Lambert.
"Charles' injury is probably worse than Jores Okore's was and that's disappointing.
"It will be a big ask for Charles to come back this season because he's not had many games at all and that Achilles heel, as everybody knows, is a major issue."