La Liga Preview: Sociedad start new era with visit from champions
Sociedad have won just once in the league this season - a shock 4-2 victory over Real Madrid in August - and slipped to 19th in the table after losing 1-0 at home to Malaga last weekend.
That result proved to be the final straw for the club's board, with Arrasate being sacked on Sunday.
Coaches Asier Santana and Imanol Alguacil took charge of training during the week, and the prospect of facing in-form Atletico - who have won their last five games in all competitions - without a boss represents a daunting one.
But ahead of the champions' visit, Sociedad captain Xabi Prieto called for fans to keep their faith despite their dismal form.
"We've had a wake-up call, the results haven't been going our way, the team hasn't been performing to the level it should and that, for us the players, means that we have failed," he said.
"We have to maintain faith in this squad because I believe we are capable of doing much better than we have been until now.
"It was a great shame to see [the coaching staff] go, although we know that these things happen when the results aren't coming - it's a real shame."
Following their qualification for the UEFA Champions League last-16 stage in midweek, Liga leaders Real Madrid - on a scintillating run of seven straight wins, with 32 goals scored in that time - return to domestic action against Rayo Vallecano on Saturday, while second-placed Valencia entertain Athletic Bilbao.
Barcelona will go in search of a return to winning ways when they travel to Almeria - having lost to Real Madrid and Celta Vigo in recent weeks.
Luis Enrique's side have slipped to fourth in the table but head to the Estadio de los Juegos having secured qualification for the last 16 of the Champions League by winning 2-0 at Ajax - courtesy of a Lionel Messi double - in midweek.
Bottom side Cordoba face fellow strugglers Deportivo La Coruna at the Estadio Nuevo Arcangel looking for a first win since their promotion while Levante - also in the bottom three - travel to high-flying Sevilla.
Unai Emery's men slipped up last time out against Athletic Bilbao but can strengthen their position among the frontrunners with a first victory over Levante since January 2011 in Sunday's early kick-off.
Celta - a spot behind Sevilla in sixth - face Granada while in-form Malaga can record a fifth straight league win against Eibar.
Elsewhere, Getafe and Elche meet at the Coliseum Alfonso Perez while Espanyol host Villarreal.