Terraces off-limits, nightstands banned in hotels around San Mamés and zones of the city under close watch are just some of the measures put in place to stop Spartak fans from wreaking havoc in Bilbao.
Police have even gone as far as to calling off extracurricular activities at local schools in order to prevent school children getting caught up in possible confrontations.
On the ground, there will be 500 members of the Basque police force, 100 municipal police officers and 200 of the club's private security guards.
So far, German police have detained one man en route to Bilbao. The hooligan was wanted for the "attempted homicide" of an England supporter during Euro 2016.
Spartak ultras are often dubbed as Europe's most violent fan force and, with Thursday's Europa League tie fast approaching, they will be keen to sow some fear in Spain.