If Lennon's men defeat Hibernian at Celtic Park on Saturday and St Mirren manage to beat Motherwell at Fir Park, the Hoops will retain their Scottish Premier League crown.
And the following weekend, Celtic can book their place in the Scottish Cup final by defeating Dundee United at Hampden Park
Some below-par performances over the last few weeks, most recently in the 1-1 draw with St Mirren, has left the manager demanding his charges return to top form over the coming weeks to finish the season in style.
"I don't think we have been complacent," Lennon said. "I just think some players of late haven't been playing to the form that we know. There is certainly no lack of complacency. I certainly didn't see any on Sunday.
"I'm just looking for a bit more quality from a few individuals. We have had a comfortable week training and are really looking forward to the game.
"We are at home and have a title to play for and these are exciting days as we have a semi-final on the back of that. It could be a momentous season for us, with qualifying for the last 16 as well."
Celtic could be boosted by the presence of Kris Commons in the side after he returned to training Thursday, despite being stretchered off against Paisley's Saints.
"Kris has been out doing some light stuff this morning and is feeling good," added the Bhoys boss. "We will see how he is tomorrow but we are pretty hopeful he will be okay. He has been in fantastic form in the last month or so and has been a real pivotal player for us."
However, injury has rendered a number of key players unavailable for selection, with doubts remaining over several others.
"We are hoping (Mikael) Lustig will be fit while (Adam) Matthews will probably still be out," said the manager. "Scott (Brown) is long-term and Lassad has been out and will start training again on Monday. The rest of the squad is pretty healthy.
"James (Forrest) won't make the weekend and we will have to see how he progresses in the next week. He's possible for the semi-final but it's a long shot.
"There is that incentive for them as well."