The German champions produced a rare off-key performance at Porto in the UEFA Champions League - succumbing to a 3-1 defeat in the first leg of their quarter-final in Portugal.
As a result, Bayern's hopes of securing a treble have been hit, although victory at the Rhein-Neckar Arena would send Pep Guardiola's men 13 points clear at the summit of the Bundesliga ahead of Wolfsburg's clash with Schalke on Sunday.
"Errors like ours are punished at this level. It’s frustrating," Sammer told Bayern's official website.
"We have to shake ourselves awake. If you want to become a great team, you have to be able to put these things behind you."
Guardiola was more philosophical in his assessment, having seen his side fight back from conceding two early goals, only to then be hit by a Jackson Martinez sucker punch 25 minutes from time.
Bayern were missing the likes of Franck Ribery, Arjen Robben, Bastian Schweinsteiger and Mehdi Benatia due to injuries, and Guardiola said: "We recovered well from going 2-0 down and controlled the match.
"I'm not totally unhappy with my team. We tried everything we could, but it wasn't easy."
Hoffenheim remain in contention for a UEFA Europa League place despite Sunday's 3-2 defeat against struggling Cologne and were buoyed by coach Markus Gisdol signing a new contract on Thursday.
After keeping Hoffenheim in the top flight during the latter stages of the 2012-13 campaign, his first full season at the helm resulted in a ninth-place finish.
Gisdol is now in with a chance of securing a place in continental competition for the club.
The new deal keeps him tied down until 2018, but Gisdol's immediate task is to shore his side up defensively, with 10 goals having been conceded in their last three outings in all competitions.
Hoffenheim have also failed to win in over a month - bowing out of the DFB-Pokal to Borussia Dortmund in the process.
However, Gisdol told reporters: "We have made progress in the last two years with giant steps. What I see here is exciting potential for development.
"I have a lot of imagination about what can happen here and in the end it was an easy decision [to sign a new deal].
"If we can establish ourselves where we stand currently, that would be great for us."
