Freiburg coach Christian Streich and Bayern Munich players Arjen Robben and Mats Hummels voiced frustration after the second half of their game at the Allianz Arena was delayed for eight minutes because of a performance by U.S. pop singer Anastacia.
The performance on Saturday was part of choreographed celebrations of Bayern's fifth successive Bundesliga title, with one newspaper describing the spectacle as "Munich's Muppet Show."
Streich, whose Freiburg side were one of several teams competing for a spot in next year's Europa League, said: "It was annoying we couldn't start to play.
"It was a football match, and the football match was the best of everything I've seen today.
"Without being disrespectful to the artist, it's a football stadium and it's madness you have to wait for eight minutes as a team."
Anastacia later performed a duet with Bayern coach Carlo Ancelotti at the club's evening celebration party.
- FC Bayern English (@FCBayernEN) 21 May 2017
Streich -- recently described as the "league's conscience" by Mainz counterpart Martin Schmidt -- said Robben had told him: "This is s---," and the winger told reporters: "I felt sorry for Freiburg because they still had something to play for."
Defender Mats Hummels added: "It was pretty unfortunate what happened at half-time. I don't think it's all that great, but it appears to be part of it these days."
Bayern later celebrated on the pitch with traditional beer showers. Some of the beer glasses used had a GoPro-cam attached to them, and the spectacle drew sharp criticism from sections of the German media.
Frankfurter Rundschau hit out at "Munich's Muppet Show," while Die Welt said: "Even Munich players were embarrassed by Bayern's title celebrations."
The champions' 4-1 win meant Freiburg finished seventh, but they would still qualify for the Europa League playoffs should Borussia Dortmund -- who have qualified for Champions League -- win the DFB Pokal final against Eintracht Frankfurt.
Freiburg president Fritz Keller, who owns a winery, told kicker: "If they can do it, a few bottles of wine will go to Dortmund."
Meanwhile, Freiburg captain Julian Schuster has extended his contract for another season.
The 32-year-old has made 230 appearances for Freiburg since joining in 2008.
"Julian has played a big part in the success of this season," sporting director Jochen Saier said on the club's official website. "We are delighted that Julian will stay with us for the coming season with his sporting and human qualities."
Schuster, captain of the team for the past six seasons, said: "I am very happy to be a part of this team, and I was able to help this team and look forward to another season in the Bundesliga."