The Scot has revealed the 33-year-old is still struggling to overcome the groin injury picked up on Euro 2012 duty with the Republic of Ireland, and may not return this term
Dunne has not featured at all for the Villans this term after picking up the injury, and suffered a further blow earlier this year after aggravating the injury during a comeback in training.
And Lambert has confirmed that while the 33-year-old is still in the process of recovery, he has no idea as to when his veteran centre-back will be able to return to action.
"At the moment, Richard is still doing his rehab but he is not back to square one,” Lambert told reporters ahead of the club's clash with Arsenal on Saturday.
"Whether he plays again this season is something that we will have to see over the next few weeks. But the season is getting shorter all the time."
The news has also dented Giovanni Trapattoni's hopes that Dunne will be fit enough in time for Ireland's World Cup qualifier with Sweden on March 22.