Lambert insists N'Zogbia's exile is purely because his recovery from an Achilles injury has yet to reach the stage where he is fit enough for the tempo of first-team training.
He said: "It's just in my opinion he isn't ready for training in the first team at the minute. It's too much for him.
"Charles has been training with the kids. His injury is the same as Christian's got. It's really bad.
"He's still really short of match fitness. You can do all the training you want, you can work with the fitness lads, but for this level of football you've got to get yourself up to top level.
"I don't think he's ready for anything like that at the minute."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball