The champions travel to Fir Park to play Motherwell in the Clydesdale Bank Premier League tomorrow night.
They then face St Mirren in the quarter-finals of the William Hill Scottish Cup on Saturday, looking to avenge the Scottish Communities League Cup semi-final defeat to the Buddies.
After that, Celtic travel to Turin for the second leg of their Champions League last-16 clash with Juventus on Wednesday night, hoping against hope to recover a 3-0 deficit from the first game at Parkhead.
Lennon said: "Obviously we have places up for grabs for the Scottish Cup and Champions League so there has been no sign of anyone taking their foot off the pedal.
"The squad is vibrant and healthy and I will use it but obviously I am mindful of the fact that Motherwell is a big game, St Mirren is a huge game for us and obviously Juventus as well.
"These are three games that will shape the season one way or the other and I will go strong in all of them."