Barcelona have to not only come back from 0-3 down against Juventus, but they may have to do so with some key figures, most notably Javier Mascherano. The Argentine missed the game against Real Sociedad after feeling pain in his left leg and hasn’t trained yet. His participation is in doubt.
Jeremey Mathieu and Arda Turan also did not train though it’s not entirely clear why that is, as Mathieu has not been reported as injured and, while Arda had been injured, he had trained with the team again already.
Also of note: Gerard Pique and Sergio Busquets did not train with the group, though this could be normal as they played against La Real.
Without Mascherano though, Barcelona will have a question of how to play 3-4-3 against Juventus as expected. Does Mathieu play again, despite struggling in the first leg? Can he? We might see Lucas Digne in the left side of that back 3.