The win kept Bayern top of the Bundesliga, but Guardiola thought his side could have played better.
"We weren't very good today," Guardiola told reporters after the match.
"In the coming week, we have time to regenerate and prepare for the trip to Hoffenheim. My players need the time.
"We've played a lot of matches in the last two months and they're a little tired, as we all saw today."