Lennon, who claimed Wanyama was worth £25m and had the talent to play for Barcelona, said the player had never shown an interest in leaving Celtic but his agent, Rob Moore, was "stirring the pot".
Wanyama is under contract until 2015 but Celtic offered him a longer deal on better terms as a reward for his outstanding form since joining from Belgian club Beerschot for £900,000 last year.
Moore revealed that offer had been rejected because the terms put to Wanyama "fell short of his expectations".
That irritated Lennon. "I'm annoyed with his agent for a number of reasons," he said. "One, I was with his agent on Monday night and he never mentioned that he was turning down the contract. "Two, it looks more like it is Victor's agent that has decided to turn the contract down.
"Three, Victor is tied to the club until 2015 so we don't have to offer him a contract. The fact we have is a goodwill gesture from us and a reward for his performances.
"Four, negotiations may be ongoing but they will remain private so long as his agent keeps things out of the public domain.
"It is not an issue for me or the club. We are quite comfortable with it all. I think the agent is trying to make a big thing. He seems to talk a lot out of school and he is trying to get the player's name out in the public domain.
"A month ago, Victor said he was very happy here and I see that every day in his performances. It has nothing to do with Victor, it is his representatives who seem to be stirring the pot a little bit. But, for the time being, he's our player and we're protecting him. We want him here until we feel it's time for him to go and we get an offer we feel befits his talents."
Lennon said Wanyama's ability as a defender or defensive midfielder was com- parable to that of Alex Song, who Barcelona signed from Arsenal for £15m in the summer. "I think he [Wanyama] can play in any company. He's very consistent and you have to look at what he could develop into as well. You look at the player he is now and where he could be in two, three, four years' time. He has been a great performer for us, as have many of the players here, but obviously there is a lot of speculation and interest in him."
Of the £25m price tag, he said. "I don't know [if that value is realistic] but it is what I value him at. I've just said he is worth £25m so they [any interested clubs] can start the bidding at that . . . "