Arjen Robben and Uli Hoeness have urged Bayern Munich not to let complacency creep in as they target a sixth win from six Bundesliga matches.
President Hoeness applauded the players for their "fantastic performance so far" and said the club was a harmonious place, adding: "It is all quiet, no spats - that's a great thing."
Speaking to Bayern's TV channel, he stressed: "We're having a lot of fun, but we have to keep it up to defend our lead."
Memories of last season - when Bayern opened up an early eight-point lead only to end up losing the title by the same margin - remain fresh, and Robben told Sport 1 TV: "Last year, we started off pretty good as well, had a good lead, but then faded and lost points.
"It is important to keep it up and not take things too easy now and think: 'Well, the next match is ours as well.' That's not how it works.
"Right now at Bayern, the feelgood factor is very high - but if you are on a good run everyone feels good and everything is positive.
"But it is important that we can argue with each other. We have to be able to tell the truth to each other, and the truth is not always positive."
Robben and team-mate Franck Ribery had a bust-up during the Champions League semi-final against Real Madrid, but he said he had forgiven the Frenchman, adding: "Ribery and I get along better now. As I already said before the season, you have to forgive.
"Ribery made a mistake last year; he apologised, and life goes on. I have forgiven him. I want to have a good time with him, on and off the pitch."
Bayern take on Werder Bremen on Saturday, and Bremen are relishing the prospect. Their Austria international Zlatko Junuzovic said: "Bayern are having a great run.
"But you can beat every team if you are not afraid. It's a sold-out stadium, there will be a great atmosphere. Anything can happen, and we are really looking forward to it."
But the Bremen defence will not have to face striker Mario Gomez who, according to Bild, is unlikely to return from an ankle injury before November.
Bayern doctor Hans-Wilhelm Muller-Wohlfahrt told the paper: "We want to get to a point where Gomez can get back on the pitch without any risks. You have to be cautious."