Wanyama's representative Rob Moore revealed back in October that the 21-year-old had turned down an extension at Parkhead, and the Kenyan has been linked with the likes of Manchester United and Queens Park Rangers.
He is under contract with the SPL champions until 2015 and Lennon hopes that talking to Moore could help to improve Celtic's chances of prolonging Wanyama's deal.
"We can always re-open negotiations with Rob on Victor's situation," said Lennon in the Daily Record. "He has another two years on his contract so we have time on our side.
"Obviously, the longer we leave it, the more vulnerable we become or the more he is an attractive proposition for a bigger club. That scenario will be a reality later on down the line. In the meantime, we will be plugging away at it.
"He has never intimated to me that he wants to leave and I am not too sure who is driving the bus in this situation, whether it is him or Rob.
"Further down the line I would like to speak to Rob again on the situation and see if we can bed him down for a little bit longer."
Lennon also reiterated his previous view that any clubs trying to tempt Celtic into selling Wanyama will need to stump up big money.
He added: "Like everything else in life, you can't stop the progression. If a bigger and more productive club came in and the offer is right then we will seriously look at it.
"I don't want to stop their progress. I will shake his hand and say 'good luck to you son'. Just so long as we get about £25million."