Diego Simeone believes Diego Costa is the most important player to feature for Atletico Madrid in recent years.

Costa returned to Atletico action this month, becoming eligible to play following a return transfer from Chelsea that was announced in September.

The Spain international laid on an assist for Yannick Carrasco as Atletico beat Lleida 3-0 on Tuesday to wrap up a 7-0 aggregate triumph in the Copa del Rey.

It means he has been involved in three goals in three games since making his return, having found the net twice already for the Rojiblancos.

Costa helped fire Atletico to LaLiga glory and the first of two Champions League finals in three seasons in 2013-14.

And Simeone was quick to lavish praise on the striker following Tuesday's win at the Wanda Metropolitano.

"I have no doubt that Costa was the most important player that has played for Atletico in recent years," said the coach.

Vitolo lashed in a late third for Atletico after Kevin Gameiro had doubled their lead, his volley marking his first goal for the club.

"He had a very good game and is integrating little by little to the needs of the team," Simeone added of Vitolo.

"He looks up, controls well, turns well, has a good transition to attack from the outside or inside, and he will have to continue taking advantage of the minutes on the pitch when the team needs him."