The Villa boss says it would cost the club millions to replace the England international, after he signed a new long term contract to commit himself to Villa Park.
“If you lose someone of that ilk it's going to cost you a fortune to replace him. It would take millions to replace him and we obviously can't do it,” said Lambert.
“I don't know what his value is, £15million? Whatever it is we're not in a position to go and do things like that at this minute in time.”
“It's great for the club he is definitely staying, it makes common sense.”
Delph signing a new deal puts an end to the speculation surrounding his future, which centred around reported interest from the Daily Mirror that Tottenham Hotspur wanted to sign him.
Former Aston Villa star Stan Collymore suggested via his Twitter account that the new deal just meant that the club could net a bigger fee for him in the summer, placing pressure on any club interested in signing him.
However, Lambert seems clear that he’s part of Aston Villa’s plans for the foreseeable future and had the club wanted to move him on or had he not wanted to sign a new deal, an exit would have happened before this point.
Delph can now get his head down and work hard on becoming an even better player on a weekly basis for the club, while the club work on improving their performances in a number of key aspects.
Villa are 15th in the Premier League table and seven points away from the top half. They will be determined to pull back that gap as quickly as possible and Delph will definitely help.