La Liga president Javier Tebas has condemned a group of Sevilla ultra fans for attempting to intimidate players at an open training session this week.
Supporters belonging to the Biris Norte group watched Monday's training and then spoke to the Sevilla captains to express their concerns over the team's recent results before leaving after an hour.
Sevilla have not won in La Liga since Dec. 2 and have lost four of their last five league games, the latest a 1-0 loss at Alaves on Sunday.
"We cannot allow this to happen," Marca reported Tebas as saying.
"To see the Biris Norte in the training ground, it reminds me of unfortunate episodes in Argentinian football.
"The fact that they attend at a difficult time for Sevilla from a sporting point of view is coercion. We are going to investigate who they are and try to expel them from Sevilla and from all football grounds.
"We cannot allow for these actions to take place. These images are shown around the world and do terrible damage to the competition."
Since taking the helm of La Liga in 2013, Tebas has worked towards eradicating the threat of ultras at football grounds.
Sevilla, who won 2-1 at Atletico Madrid in the Copa del Rey quarterfinal first leg in midweek, travel to Espanyol on Saturday.