The pair are on loan at Brighton but will return to Aston Villa next Friday if extensions are not agreed.
Lambert said he will weigh up his options over the Christmas period before deciding what to do with the duo.
But with Sami Hyypia quitting his role as the Seagulls' manager yesterday the pair may not be wanted at the AMEX Stadium anyway.
Lambert said: "I know they come back pretty soon but I haven't decided (about an extension) yet."
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!