PSG visited Bayern's Allianz Arena on Tuesday and a section of the home support unveiled a banner with a profanity aimed at the "plutocratic Al-Khelaifi".
"We concede a lot of goals because we are not stable," complained Guardiola.
Bayern Munich striker Harry Kane hit back at criticism levelled at him, saying he would do his "talking on the pitch" after becoming the fastest to 50 goals in Bundesliga history on Friday.
The German giants, who went without a trophy last year for the first time since 2012, are primed for a return to the winner's circle.
Struggling in Europe after back-to-back losses left them outside the knockout places, Musiala broke through the stubborn Benfica defence, heading in a Harry Kane assist.
Bayern Munich will learn from their 4-1 Champions League defeat to Barcelona but the German team's belief in a successful season is intact, coach Vincent Kompany said on Saturday ahead of Sunday's league game against VfL Bochum.
Bayern Munich coach Vincent Kompany and his Bayer Leverkusen counterpart Xabi Alonso on Friday joined the growing chorus calling for action on player workload, amid talks of strikes.
A street next to Bayern Munich's Allianz Arena stadium will be renamed to honour German football great Franz Beckenbauer who died earlier this year, the city council announced Thursday.
"Something big is coming," Neuer told reporters ahead of Tuesday's opening clash with Dinamo Zagreb at home.
"What do I think we were missing? In training we show what we can do much better because we are courageous, because we play football freely," Mueller said.
Xabi Alonso's unbeaten Bayer Leverkusen took control of the Bundesliga title race on Saturday, thoroughly outclassing Bayern Munich in a 3-0 home win to go five points clear at the top of the table.
Harry Kane scored the go-ahead goal to help Bayern Munich to a 3-1 comeback home win over Borussia Moenchengladbach on Saturday, keeping hot on the heels of leaders Bayer Leverkusen, who won 2-0 at Darmstadt.
Xavi's announcement on Sunday that he will leave Barcelona at the end of the season has sparked a flurry of speculation about his possible successor.
Bayer Leverkusen were held to a goalless draw at home to Borussia Moenchengladbach on Saturday as their lead over injury-hit Bayern Munich at the top of the Bundesliga was cut to two points.
The Bayern Munich manager said he felt "a little bit jinxed" by the club's injury misfortunes
Bayern Munich's Allianz Arena will bid a final farewell to Franz Beckenbauer on Friday as tens of thousands of people pay their respects to the German football legend.
"I've known Eric for a long time, played with him for a long time, and I know what a great player he can be for us," Kane said.
Jamal Musiala scored twice and Harry Kane added a late goal as Bayern Munich won 3-0 at home over Hoffenheim on Friday as the club celebrated the life of Franz Beckenbauer.
In an interview with the Bundesliga website, Tuchel said it was "very striking to me that he's so, so humble".