The Celtic boss confirmed on Friday that the Scottish champions had rejected an offer, reported to be about £5million.
Lennon, who is hoping to keep his squad intact for next month's Champions League last-16 clash with Juventus, said: "I thought Gary was brilliant, he was at his best. He got two goals, but I think his all-round game was top class."
He added: "We had a chat after speaking to his representatives and we wanted to make our position clear to him and he is quite comfortable with it all. We have made it clear that we are not selling him, we don't want him to go, especially at this juncture of the season.
"However, everyone has their price and what Gary's price is will be down to the board and myself to decide. What we were offered on Thursday was nowhere near our valuation of the player.
"We don't have a set figure, however, goalscorers are at a premium and Gary is a goalscorer so we will set the bar pretty high for him. I am hearing that they (Norwich) might come again but good luck to them on that."
Lennon stressed that he would not unnecessarily stand in the way of Hooper moving on to bigger things.
He said: "He is at a big club as it is and he is in the Champions League. His ambition possibly is to play in the Premier League and I think he is good enough to do it now, there is no question about that. It just depends on the level he wants to play at and I don't think he is far away from international level as well."
Hearts boss John McGlynn was happy that his young side at least stayed in contention after falling behind to two early goals.
He said: "The only positive is that after being two down after 15 minutes, we had the chance to win it with five minutes left, because many teams would come here and possibly crumbled."
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