Musiala missed the draw with Eintracht Frankfurt shortly before the international break, was ruled out of Germany's UEFA Nations League games last week, and could not recover in time to face Stuttgart at the weekend.
However, reports claim the 21-year-old has stepped up his work to be fit for the high-profile encounter in Spain this week, with a hip issue currently making him a doubt.
Thomas Muller will be waiting in the wings if Musiala does not make it though, and the Bayern legend will look to add to his impressive tally of eight goals in nine career appearances against Barca.
One player who is certain to feature will be Harry Kane, after he scored his sixth Bayern hat trick in the 4-0 win on Saturday, the fifth of which came on matchday one of this competition against Dinamo Zagreb.
There was some bad news in the aftermath of the weekend win though, as Aleksandar Pavlovic is set for a few months out after breaking his collarbone in the opening minutes of the game.
Joao Palhinha is the likeliest candidate to come in to partner Joshua Kimmich in the engine room, especially if manager Vincent Kompany opts to use Konrad Laimer as a full-back.
With Sacha Boey and Josip Stanisic both currently injured, Raphael Guerreiro has been forced to fill in on the right-hand side of defence, but did not feature against Aston Villa on matchday two.
Kompany has four options to use out wide, but it is likely he will stick with Michael Olise and Serge Gnabry, who both started at the weekend, leaving Kingsley Coman and Leroy Sane in reserve.
Bayern Munich possible starting lineup:
Neuer; Laimer, Upamecano, Kim, Davies; Kimmich, Joao Palhinha; Olise, Muller, Gnabry; Kane