The defender declared himself fit for a UEFA Champions League game against Juventus in February after flying in from the Africa Cup of Nations, but produced a poor performance in a 3-0 defeat and was even criticised by team-mate Kris Commons.
He has been away with Nigeria again this summer, at the Confederations Cup, and Lennon has promised that this time he will not come back too soon.
The Celtic boss says Ambrose needs some time off ahead of the new campaign, even if that means he does not play much of a role in pre-season.
Reflecting on what happened against Juventus, Lennon said in the Sunday Mail: "Aye, we'll learn from that one.
"He won't be back until the 15th, so he'll miss a huge chunk of pre-season.
"Efe's a fine athlete but he needs rest."