The Hoops currently sit 11 points clear at the top of the Scottish Premiership after going unbeaten in the 18 games so far, registering their seventh win on the trot with a 1-0 victory at Inverness on Sunday.
Despite this commanding position in the league, Lennon is not resting on his laurels and wants to add more depth to his side after selling Victor Wanyama and Gary Hooper in big-money deals to Premier League outfits Southampton and Norwich over the summer.
He said: "It has been a really good two years. We've sold £20million worth of players and that's a big deal for the club.
"To replace those players you need to spend £20m and we are not in a position to do that. But we are unbeaten and the players deserve a lot of plaudits.
"We are hoping to start getting into the market over the next week or so. We've made slight inroads but are nowhere near anything."
Reports after the win at Inverness suggested Lennon did not know of a formal offer for Al-Ahly playmaker Hassan, and the Egyptian club's general manager Mohammad Yousuf confirmed no official bid has been made.
But the 19-year-old, nicknamed Trezeguet in Egypt after France's World Cup winner David, claims a bid has been made and he has told the club he wants to join the Scottish champions.
Hassan was quoted by the Daily Record as saying: "Celtic made a bid of 500,000 euros and I think that's a very fair offer.
"The club have refused the offer because they insist they need me - but they have a couple of players coming into the club in January.
"Celtic are a big club and their coach told me he wants me. They watched me at the Club World Cup.
"I think it would be an important step in my career to move to a bigger club.
"I've informed the club I want to leave and I hope they grant me my wish."