While Messi continues his recovery from a hamstring injury in his native Argentina, Neymar is suspended after being booked late in a 2-1 La Liga win over Villarreal last weekend.
The absence of the Brazilian is a blow to Barca, with Neymar having scored six goals in his last three matches for the club.
The 21-year-old has flourished without Messi and scored a UEFA Champions League hat-trick against Celtic earlier this month.
Barcelona still have good options in attack - Alexis Sanchez and Pedro have scored 15 La Liga goals between them this season - and manager Gerardo Martino is confident his side can cope.
"We will miss him (Neymar). He has settled in really well at the club and he is already very popular," Martino said.
"But we have other forwards who can cause problems for Getafe."
Barca could be three points behind Atletico Madrid by the time their match kicks off on Sunday, with Diego Simeone's side in action against Levante one day earlier.
Just one side - Atletico - have conceded fewer goals than Barcelona, while Real Madrid, five points back in third, are the only side to have scored more.
Getafe sit eighth in the table and enter the match on the back of a morale-boosting 4-1 Copa Del Rey win over Girona.
Getafe were hammered 7-0 by Atletico last month, but will be determined to prove that result was an aberration.
Club president Angel Torres believes this is the ideal time to face Barcelona.
"Let's see if we can get them this time, it's a good moment for it," Torres said.
"Messi is the best player in the world and Neymar is coming into good form, but it must be said that they have plenty of backup. We will have to play at 150 per cent on Sunday.
"We will have a go. We did it in 2007 (when beating Barca 2-0) and we will give it the best possible shot."
Goalkeeper Victor Valdes is fit again after a calf injury but likely to miss out for Barcelona, with Dani Alves (calf) and Xavi (leg) also potential absentees.
Barcelona have beaten Luis Garcia's men in their last three league meetings, scoring 14 goals in the process.
