The Manchester United boss - an ex-Rangers player - has offered his Hoops counterpart regular "tit-bits" of advice as the Parkhead side battled through two qualifiers before coming second to Barcelona in their group to take them into the knockout stages where they were paired with the Italian giants.
Lennon said: "Sir Alex took time out of his heavy schedule to come and visit me and my backroom team one afternoon and throughout the campaign we have been in touch.
"He has gone out of his way at times to help us, not in a huge way but little pointers in the right direction, with little tit-bits of advice for what to look out for and for a young manager he is fantastic in that way.
"Obviously we are up against a great team and great coach and it is very exciting for me to challenge myself against Antonio Conte.
"I don't want to fill the players' heads too much from a tactical point of view.
"And in terms of motivation, I don't think the players need any more from me.
"It is probably the biggest game of some of their young careers and we are hoping we can take the club further in the competition.
"We've always known this has been looming on the horizon so it is almost here and I think we are ready."
While most people see Juventus as strong favourites to win their way through the tie, Conte said: "If anyone has underestimated Celtic, it has certainly not been us. We have great respect for them.
"We have followed Celtic very closely and they were very strong against Spartak, Benfica and Barcelona and even before that in the qualifiers.
"They are a very good team. To beat Barcelona here at Celtic Park and to go close in the Nou Camp is proof of that.
"We are going to have to be very careful tonight [Tuesday]."