The Brazil international is suffering from gastroenteritis and has been advised to rest by club doctors, resulting in Xavi being added to the Blaugrana squad.
The Brazil international had been expected to start at Camp Nou after only featuring as a substitute in Sunday's 4-0 win over Elche, but the Blaugrana have revealed that the attacker has been forced to withdraw from the squad due to illness.
"Xavi Hernandez comes into the squad for the last-16 game tonight [against Getafe] to replace Neymar, who is suffering from gastroenteritis," a statement on the club's official website read.
"After the visit of the club doctors, they have recommended that he rest and he has, therefore, gone home."
Barcelona will now be sweating on the availability of Neymar for Saturday's La Liga showdown with Atletico Madrid at the Vicente Calderon.