The Irishman returned from suspension against St Mirren yesterday, but spurned a host of decent scoring chances as the champions extended their unbeaten run to 24 matches with a 1-0 win.
Griffiths was paraded in front of the Parkhead crowd at half-time and could make his Hoops bow in the Scottish Cup clash with Aberdeen this weekend after completing his £1million move on Friday night.
Kris Commons got the only goal of the game to stretch Celtic's advantage at the top of the SPFL Premiership table but Stokes attracted the ire of the home crowd as he failed to find the net from a series of promising positions or set up Derk Boerrigter when Celtic broke late on.
Lennon said: "Stokes should have squared it at the end. It's about decision-making.
"He only had to roll it to Derk and it was 2-0 and game over. That was a bit disappointing.
"Signing Leigh just gives us another striker in, but I thought Stokesy played well today.
"His movement was good and he just lacked a goal. Maybe that was what he wanted at the end but he has to make sure he scores if he goes himself."
While Lennon was left frustrated that his side didn't hammer home their advantage against the Buddies, the Parkhead boss could have no complaints about their defensive resolve as they recorded yet another clean sheet.
Keeper Fraser Forster has now clinched his place in the history books after his notching his 11th successive shut-out as he surpassed Charlie Shaw's century-old landmark of 10 consecutive league blanks.
And he is now only four games away from the world record for consecutive clean sheets.
Lennon said: "It's something to aim for.
"It's something that really keeps our season alive.
"I think we're pretty clear in the league now, so that's a yardstick for the players to try to achieve.
"That and keeping the unbeaten record going. That's 24 games and I can't ask any more of them really.
"We've just hit a really good vein of form in terms of our football, and I'm enjoying the way we are moving and passing the ball.
"These are special times for the players. When they look back on their time here, they can reflect on this as quite an achievement.
"I thought we had total control of the game and we had some great performances - particularly Stefan Johansen on his debut.
"It was as good a debut as I have seen in my time as manager here.
The only thing that was missing was the couple more goals that would really have emphasised our superiority."