Barcelona's squad planning has been called into question by Sergio Busquets, who voiced his concerns over the lack of options for head coach Quique Setien after a 1-1 draw against Napoli.
Barca escaped Stadio San Paolo with a positive result on Tuesday night despite being second best for large portions of the game.
The Spanish champions failed to muster a single shot on goal in the first half, with Napoli taking the lead on the half-hour mark via a superb Dries Mertens strike.
The home side had chances to extend their lead, before Antoine Griezmann hauled Barca level in the 57th minute after turning home Nelson Semedo's low cross.
Arturo Vidal was sent off late on and will miss the return leg at Camp Nou on March 18, as will Busquets, who has also been hit with a suspension after picking up a yellow card in the second half.
Gerard Pique is now facing a spell on the sidelines too after limping off the pitch with an ankle problem in stoppage time.
With Luis Suarez and Ousmane Dembele set to miss the remainder of the season through injury, Setien has been forced to dip into the academy for extra reinforcements, with four B team players named on the bench in Naples.
Barca's squad will be stretched to the limit in the reverse fixture and Busquets has appeared to criticise the club for failing to take pre-emptive measures in order to avoid such a scenario.
"Semedo and I were one booking away from a ban so we were always running that risk [of suspension]," he said post-match, as quoted by ESPN.
"We hope Pique's injury is nothing serious but we will take on the second leg with what we have. We don't have a deep squad because, unfortunately, that's how it was planned."
Croatian midfielder Ivan Rakitic echoed his team-mate's sentiments, stating: "We have a short squad but those that are in charge knew that.
"The solution is what it is. Those that are available will have to work really hard because we have an important match in the second leg."
Setien will now start preparing his players for a huge Clasico showdown against Real Madrid at Santiago Bernabeu on Sunday.
Barca moved two points clear of their arch-rivals in the Liga standings after beating Eibar 5-0 at Camp Nou last weekend, with the Blancos having slumped to a 1-0 defeat against Levante.