The 24-year-old, on loan from Bayern Munich, has hit 11 goals in 24 matches for the Bundesliga strugglers, who lie 14th in the standings, six points clear of the relegation play-off place.
“I’m a firm believer in taking responsibility in your actions,” he told the German media. “If you made the mess, you must clear it up.”
Despite his scoring exploits – Bremen have hit more goals than fourth-placed Eintracht Frankfurt – the club have been poor defensively, conceding more than any other side in the division.
And while the club’s woes lie at the opposite end of the pitch, Petersen insists he must take his share of the blame.
“I ultimately carry fault in this situation too,” he added.
“I believe in the team performing as a unit, and I know what we must do.”
Petersen is expected to discuss a permanent transfer over Easter.