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.
Borussia Dortmund's dream of their first Bundesliga title in 11 years turned into a nightmare on Saturday after a shock 2-2 home draw to Mainz 05 dropped them to second place on goal difference in the season finale, handed the title to rivals Bayern Munich.
Bayern Munich spectacularly snatched their 11th consecutive Bundesliga title with a last matchday 2-1 win at Cologne on Saturday courtesy of Jamal Musiala's 89th minute winner, grabbing the trophy from the hands of rivals Borussia Dortmund.
Two points clear atop the table, Dortmund can win their first title for 11 seasons by beating Mainz at home on Saturday, regardless of second-placed Bayern Munich's result at Cologne.
Bayern remain in top spot on 68 points but Dortmund, on 67, are in action at Augsburg on Sunday and a win would see the Ruhr valley club go into next week's season finale in the driving seat
Pep Guardiola's City, who are on the cusp of retaining their Premier League crown, will play his former side Bayern and Japanese champions Yokohama F Marinos in friendlies in Tokyo.
Serge Gnabry and Kingsley Coman scored late to snare all three points for the Bavarians, who are now one point clear of Borussia Dortmund with four matches to go
Bayern Munich full-back Alphonso Davies has been ruled out of the club's "upcoming games" with a hamstring injury, the German side announced on Sunday.
With Bayern in control and leading 1-0 at half-time after Sadio Mane's first goal since October, the visitors conceded three goals in 14 minutes
Dortmund host Eintracht Frankfurt later in the day and can go one point clear with a win, with five league matches remaining this season.
Manchester City cruised into the Champions League semi-finals after a 1-1 draw at Bayern Munich on Wednesday secured a 4-1 aggregate win that moved them a step closer to an elusive first title in the competition.