Agbonlahor's current deal at Villa Park expires in 2015, with the forward on record as stating that he wants to retire at the club he joined as a youngster.
Lambert believes that next summer is a more appropriate time to discuss fresh terms with both Agbonlahor and Fabian Delph, while admitting that he is frustrated with the former England international's current spell on the sidelines.
He told the Birmingham Mail: "When you look at 15 months it's still a long time in football. In years gone by you used to never find out what was happening to you until about a week before the end of the season.
"I understand what he's saying but I think there's a long, long way to go before anything like that. I think he's enjoying his football. I think you look at all these sort of things at the end of the season, for everybody.
"It's a bit frustrating he's injured at the minute. But the important thing for me is for him to come back fit and get that ankle sorted."
The 27-year-old, who is still searching for his first Premier League goal of the campaign, is currently out injured nursing a niggling ankle problem.