The striker has been linked with a move away from the SPL side, with a number of Premier League teams thought to be interested in the 23-year-old.
"I don't need to speak to the board, they know my position. Everyone has their price. We are not a selling club but everyone has their price," said Lennon.
"The problem is if we get a knockout price, will we have time to replace someone like Gary Hooper? Trust me, they are hard to find.
"I have spoken to Gary, I am keeping him up to date. I think he is very happy here. I think Celtic and Gary suit each other, he is a Celtic type of player, strong, great finisher, great feet and his goal record speaks for itself."
The Bhoys are currently top of the SPL table after Saturday's 2-1 win against St Johnstone.