Former Poland striker Smolarek dies at 54
Grzegorz Lato, who played alongside him in that side and is now the president of the Polish FA, said in a statement: "It's hard for me to imagine. Wlodek was my friend, a buddy from the field. He was the team's good spirit."
Smolarek, whose son Ebi also became a Polish international, is the first member of that squad to pass away, said its outstanding player Zbigniew Boniek.
"At first glance he was taciturn, but he was cocky and self-confident on the pitch," said Boniek, who also played with him at Widzew Lodz and the national team before he joined Juventus.
"We played so many games together in Widzew or with the white eagle on a Polish shirt, it is such a shame," he added.
Smolarek was capped 60 times for Poland, and scored their first goal in the 1982 finals in a 5-1 win over Peru as they began their unlikely passage to the last four.
They finished top of the first round group ahead of eventual world champions Italy and progressed to the semis after a win over Belgium (3-0) and a 0-0 draw with the Soviet Union in the second round.
They were beaten 2-0 by Italy in the semi-finals but beat France 3-2 in the third-fourth place play-off.
In 1986 Smolarek joined Eintracht Frankfurt and two years later moved to the Netherlands where he played for Feyenoord and Utrecht.
His son Ebi plays at ADO Den Haag in the Dutch League after spells at Feyenoord, Borussia Dortmund and Bolton Wanderers.