Despite making an unbeaten start to the season with four wins and a draw, Sammer took exception to the first 45 minutes of Saturday's 2-0 win over Hannover and demanded an immediate improvement from the team.
"We need more emotion," he said. "We were lethargic at times and that's not enough for the level we want to be at."
That level was shown last season when Bayern broke record after record on their way to an historic Bundesliga, Champions League and DFB-Pokal treble.
If they are to defend their European crown this season, they will have to break another record as no side in the history of the competition has won back-to-back editions.
"Of course we want to be the first to do that," defender Jerome Boateng told his club's website.
"But this is just the beginning and we're not thinking about that yet. We're taking things game by game and, right now, our priority is to make a good start to the group.
"We want to go as far as we can and to do that, we've got to be on fire from the beginning."
Boateng accepted Sammer's criticism, saying he was right to remind the players of their responsibilities.
"Matthias doesn't say things if there's nothing to be said," Boateng added.
"I think the team will take it on board. We now have a busy programme of games and we've got to put our foot down."
At the weekend, coach Pep Guardiola fielded his seventh different team in seven competitive matches this season, including the pre-season Supercup, and more changes can be expected against CSKA with Bastian Schweinsteiger back in the reckoning.
The Germany international was only a substitute at the weekend, but his return could permit Philipp Lahm to return to his habitual full-back position.
Midfielders Javi Martinez and Thiago Alcantara are still sidelined, though, while striker Mario Gotze only returned to training on Sunday for the first time since injuring his ankle in the UEFA Super Cup win over Chelsea.
A look at the statistics will give Bayern reason to be optimistic - they have won their last nine opening Champions League fixtures, including victory over CSKA's Moscow rivals Spartak in 2006.
The side who have made three of the last four finals will therefore fancy their chances of making another winning start, but CSKA arrive fresh from a 1-0 win over FC Rostov which extended their unbeaten start to the Russian Superleague season to eight games.