The former Hibernian and Falkirk boss took over the Highland club earlier in the month following the departure of Terry Butcher, who took over the reins at Easter Road.
The Hoops could hardly be in better shape following their 1-0 win against St Johnstone at McDiarmid Park on Boxing Day, courtesy of a wonderful Virgil van Dijk goal.
They sit 11 points clear at the top of the table and looking to make it 18 league games unbeaten since the start of the season.
However, the Celtic boss is bracing himself for something different from Hughes' side who are in third place, just one point behind Motherwell and with a game in hand over the Steelmen.
"I'm not sure what to expect because it's difficult to replace someone who made the sort of impact Terry did," said Lennon.
"He was part of the furniture up there but John has come in and he'll want to hit the ground running as quickly as possible.
"I suppose there's no better game than one than against us.
"But we have our own targets and our own agenda. So we'll be as strong as we can and play as strong as we can."
Lennon will reshuffle his squad against Caley, who fought out a goalless draw against Partick Thistle at Firhill in their last outing.
Adam Matthews returned from a fever to start against St Johnstone but was replaced early in the second-half by winger James Forrest who continued his recovery from a thigh strain.
Charlie Mulgrew is a doubt with a groin injury while Dirk Boerrigter (hamstring), Mikael Lustig (hip), Beram Kayal (foot) and Steven Mouyokolo (Achilles) remain out.
The Northern Irishman said: "We have tried to balance the squad because we have two really hard away games back-to-back.
"Particularly Adam and James. Adam is still recovering from the virus and he was a bit heavy-legged in the second-half but I think he'll be in contention for Sunday.
"James will be in contention for a start and I don't think we have any fresh injuries which is a good thing.
"The squad is a bit thin, we have six or seven out at the moment.
"But the players who have been the bulk of the side have been great, we're unbeaten and I can't ask any more."
Inverness manager John Hughes has urged his players to be inspired by the challenge of ending Celtic's unbeaten league record.
Hughes, whose side drew 0-0 at Partick Thistle on Boxing Day, said: "They are trying to go the season unbeaten, they have the best players in the league, but that's a challenge that has to inspire the players so hopefully that will be the case on Sunday."
Hughes is hoping that striker Billy McKay overcomes a knock to play but he will definitely be without captain Richie Foran.
The Irish midfielder suffered a dislocated shoulder in the 4-3 defeat by Aberdeen last weekend and Hughes admitted his absence was a "massive" blow at Firhill.
But he praised Danny Williams for his performance in central midfield in the Irishman's absence.
Williams, 25, was making only his second start since joining from Kendal Town in the summer and is usually a left-winger.
Hughes said: "The question was asked before the game how we would get on without him and I felt Danny did really well, and really grew into the game as it went along.
"He is just a young kid who was flung in at the deep end and he really played his part.
"Any team would miss Richie, but we need to get on with it."
Hughes, who is still awaiting a full diagnosis of Foran's injury, added: "All I can say on Richie is that, worst-case scenario, it will probably be a couple of months.
"We are just hoping it's not worst-case scenario. And, if it's not, then fingers-crossed we will get him back sooner rather than later."