Jupp Heynckes insists Bayern Munich will not underestimate Celtic as they look to kill off the Hoops' dreams of the Champions League last 16.
The veteran boss has been lured out of retirement following the sacking of Carlo Ancelotti.
The Italian was axed after Bayern were beaten 3-0 by Paris St-Germain last month - a result which raised hopes at Parkhead that Brendan Rodgers' team might spring a surprise by snatching second in Group B from under the Germans' noses.
But Heynckes - who has twice won the competition as a boss and is now back for his fourth stint in charge of Bayern - is taking nothing granted as he looks to get Munich back on track.
Speaking at his final press conference ahead of Wednesday's Allianz Arena showdown, the 72-year-old said: "You can always lose a game in the Champions League, but FC Bayern have great ambitions. You cannot make the mistake of underestimating Celtic.
"They've won the league in Scotland six years in a row and last season drew with Borussia Monchengladbach and Manchester City in the group stages. They have a very good coach.
"They're powerful and aggressive. They're a very competitive team, so we need to be prepared."
That message has clearly been taken on board by Munich's superstar line-up, with Germany defender Jerome Boateng adding: "Celtic are a good opponent who can break very quickly and have very fast players. But we want to be on the front foot and score quickly if we can.
"We want to bounce back after the PSG loss with a win. Tomorrow is an important game."
Heynckes was controversially dumped by the Bavarian giants back in 2013 despite leading them to Champions League glory against rivals Borussia Dortmund at Wembley.
Pep Guardiola was hired to make that kind of triumph a regular occurrence but when it proved a feat too far for both the Spaniard and then Ancelotti , Bayern once again turned to Heynckes in the hope that he can restore unity to their dispirited squad.
Saturday's 5-0 drubbing of Freiburg was the perfect start and now Heynckes wants to build momentum by downing Celtic.
"Of course the Champions League is a competition that has a special sparkle and meaning," said the former Real Madrid boss. "The club has big ambitions in it, as do the players and I.
"It's fun to work with the squad. I see how hard the players are working and it's only a matter of time before we play really good football. "
Munich will be without two of their biggest stars, with keeper Manuel Neuer and French wideman Franck Ribery out long-term.
Heynckes' options have been further limited after Spanish midfielder Javi MartÃnez suffered a shoulder injury at the weekend but former Juventus playmaker Arturo Vidal will be fit.
"The players are fired up," he added. "But I'm not a friend of using injured players, so I've agreed with our doc that Javi won't be used. However, Arturo is back to normal and has trained well."