Blackpool are keen to sign McCourt ahead of their debut season in the Premier League but Lennon wants to keep the Northern Ireland international at Parkhead.
"We have offered Paddy a two-year extension and the ball is in his court," he said.
"I am aware of interest from elsewhere but we would like to keep him."
Celtic finished their North American tour with a match on an artificial surface against the Seattle Sounders on Sunday and Lennon admitted he had some minor injury concerns after the match.
However, Glenn Loovens, Thomas Rogne (both hip), Scott Brown (foot) and Joe Ledley (hamstring) are expected to be fit for next week's Champions League opener against Sporting Braga.
Efrain Juarez is set to miss out though after returning to Mexico to arrange a visa after completing a medical with Celtic in Seattle ahead of his move to Parkhead.