Barca was hit with a spate of COVID-19 cases during the winter break, with as many as 10 players testing positive for the virus.
One of those, Samuel Umtiti, has since returned a negative test meaning he is technically available for the Mallorca trip, but he is not deemed match fit after being unable to train over the past week.
Additionally, Xavi is without five players through injury; Sergio Busquets is suspended; Yusuf Demir is negotiating his departure; and Ferran Torres, who is injured anyway, cannot be registered until Tuesday (AEDT) at the earliest.
While postponements have become commonplace in other competitions, such as the Premier League, regulations in LaLiga make such situations much more rare.
Teams will still have to play so long as they have 13 available players from their first and second teams. Clubs must continue to adhere to the rule that dictates a minimum of seven players registered to the senior team are on the pitch at the same time.
But that minimum can drop to five players if teams have fewer than seven professionals available for selection – essentially, as long as Barca can name five first-team players in a starting XI, its games will not be postponed, much to the frustration of Xavi.
"It makes no sense to play tomorrow," Xavi said in Sunday's (AEDT) pre-match news conference.
"We are in an extreme situation. We have between 17 to 18 casualties, it depends on Umtiti, who today has tested negative but has not trained for a week.
"It's a time to suspend the game. In this way [not postponing the game], the competition is adulterated, it is crazy to play like this.
"We have no choice but to compete with who we have. Mallorca has also asked for it [the game to be postponed].
"We must appeal to common sense. It's not a complaint, it's a reality. Basketball has been suspended.
"We will play if LaLiga forces us. We've trained well, but it's a chaotic situation. Be that as it may, we will go out to compete and try to win."
Barca heads into its first game of 2022 seventh in LaLiga, 18 points adrift of leader Real Madrid.