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.
Champions Bayer Leverkusen edged past Augsburg 2-1 on the last matchday on Saturday to become the first team in the history of the Bundesliga to complete a full season without a loss.
Bayern Munich coach Thomas Tuchel confirmed on Friday he will leave the club at the end of the season, saying he "couldn't agree on terms" to stay on.
Bayer Leverkusen stretched their season-long unbeaten run to 50 games with a 5-0 win at 10-man Bochum on Sunday.
"For a goalkeeper who's been around for a while it's something I've already experienced, but the goal was brutal."
Real Madrid showed they remain Europe's comeback kings.
"The first error is made by the linesman, the second comes from the referee," Tuchel said.
Six-time Champions League winners Bayern Munich head into Wednesday's second semi-final at Real Madrid, looking to change the narrative surrounding their disappointing season.
Bundesliga champions Bayer Leverkusen extended their season-long unbeaten run to 48 games with a 5-1 win at Eintracht Frankfurt on Sunday.
Bayern, who are in second place on 69 points, two ahead of Stuttgart in third with two games left, face Real in Spain on Wednesday after their 2-2 draw in Munich.
Toni Kroos has not decided where his future lies but his team-mates are hoping he chooses to stay at Real Madrid after his Champions League masterclass against Bayern Munich.