Espanyol said on Thursday a two-game stadium closure was a "disproportionate and unjust" punishment after their fans invaded the pitch and chased Barcelona players down the tunnel.
Barca clinched the Spanish title at Espanyol's stadium on May 14 and celebrated at fulltime, provoking anger among Espanyol supporters, who stormed the field.
"Espanyol wants to show their total disagreement with the, in our opinion, disproportionate and unfair sanction imposed by the (Spanish federation's) Competition Committee on the club which would mean the closure of the Stage Front Stadium for two matches," said Espanyol in a statement.
Espanyol said they would appeal a potential two-game stadium closure, which the Competition Committee has not yet officially announced.
The Catalan side were relegated last season and if they are unsuccessful, the Stage Front Stadium will be closed for second division matches against Racing Santander and Amorebieta.