(CNN) -- Lazio, which has slumped to mid-table after collecting one win in its last eight Italian league games, fired manager Vladimir Petkovic and replaced him with veteran Edoardo Reja.
"Lazio communicates that it has terminated the employment contract with Vladimir Petkovic for just cause following the conclusion of a disciplinary procedure," the club said in a statement on its website.
It added that it had heard the "justification" of concerned parties but didn't say what the "just cause" was.
Petkovic, who in December signed a contract to become Switzerland's manager following the 2014 World Cup, is reportedly planning to take Lazio to court.
Petkovic led Lazio to the Italian Cup last season -- it beat city rival Roma in the final -- and a seventh-place finish in the top flight.
This season, however, has seen Lazio suffer lopsided losses to Juventus, Roma and Napoli -- currently the top three in Serie A.
In its last league outing prior to the Christmas break, Verona thumped Lazio 4-1.
Reja has coached about 20 teams in a roughly 25-year career and guided Lazio before Petkovic's arrival.
The 68-year-old's first game in charge comes Monday against Inter.
Atletico regains Liga lead
In Spain, Atletico Madrid and Barcelona continue to play musical chairs atop La Liga.
Atletico regained the lead Saturday when it scored midway in the second half to beat Malaga 1-0 on the road.
But this time it wasn't leading scorer Diego Costa who found the back of the net. Instead, Koke registered the winner off a rebound from close range in the 70th minute.
Atletico rose to 49 points, though Barcelona can go top if it defeats Elche at home Sunday.
The top two meet next week in Madrid.
"It would be so much nicer to be in this position at the end of the season, but there's a long journey ahead," Atletico manager Diego Simeone told the club website.
Barcelona forward Lionel Messi won't be risked for the game against Elche but Barca manager Gerardo Martino says the multiple world player of the year has looked like an "assassin" in training since returning from a leg injury.
"Messi has the eye of an assassin," Martino told the club website. "He's come back in good shape. He's done well in three training sessions."