Neil Lennon is in the dark over how Celtic's final Champions League opponents Spartak Moscow will approach their task at Parkhead on Wednesday.
Caretaker manager Valery Karpin, 43, took over for a second time at the Russian club after Spaniard Unai Emery was dismissed following a 5-1 thrashing by city rivals Dynamo last week.
Spartak, beaten 4-2 at home by Zenit St Petersburg in the Russian Premier League on Friday night, are already consigned to the bottom of Group G but will have a say in who joins Barcelona in the last 16 of the competition in the new year.
That team will be Celtic if Lennon's men better Benfica's result in the Nou Camp.
The Parkhead boss, whose side won 3-2 in the Luzhniki Stadium in October, said: "We know a lot about Spartak, obviously we have played them already.
"We have analysed their matches, home and away and we will study them again before we start preparing for the game.
"They have a new coach in, Karpin, although he has been there (at the club) a long time.
"Whether that changes the attitude of the players....it might be a good thing or bad thing, I don't know."
The visit of Spartak is just one of eight games Celtic will play in December.
However, the former Hoops skipper played down the possible effects of a "heavy schedule" on his squad, which is bolstered by the return of Emilio Izaguirre and Thomas Rogne who have recovered from hamstring and calf injuries respectively.
"That is just the reality of it," said Lennon. "It is nothing new for us.
"This season has been game after game after game.
"The challenges are there for the players.
"Christmas is always a heavy schedule but we have got the extra SPL game against Dundee United at home.
"It is a course of games to get our teeth into and we are really looking forward to it."
Lennon is considering rewarding his players, though, by taking them abroad for warm-weather training during the winter break in January.
"We will certainly give them the first week off and then have a week's training," he said.
"Whether we go away or not, we are still working on that.
"I hope to go somewhere warm, that would be beneficial, a change of environment and a change of climate, but we are still having a think about it."