Belgian playmaker Eden Hazard's form ahead of the FIFA World Cup™ has sparked a feverish debate in his home country, where one former international has called for the Chelsea star to be dropped.

Belgium have been tipped as a team who could upset the favourites at the World Cup, but two-tournament veteran Marc Degryse says 23-year-old Hazard looked worryingly distracted during the two warm up games before their Group H campaign starts against Algeria on 17 June.

Belgian coach Marc Wilmots should have a sharp word with Hazard, despite his goal in Belgium's 2-0 win over Sweden last Sunday, said Degryse, who played with Wilmots in the national side. His criticism echoed Chelsea manager Jose Mourinho after Chelsea lost 3-1 at home to Spanish side Atletico Madrid in the UEFA Champions League semi-finals.

"He has to work harder defensively," said the 48-year-old Degryse, who scored 23 times in 63 appearances for Belgium.

"Against Sweden he switched off several times, just like he did in the Champions League for Chelsea against Atletico Madrid. If that doesn't change, Wilmots will have to resolve it by dropping him."

If he plays badly I will not hesitate to replace him.

Marc Wilmots, Belgium coach

Hazard moved to the English Premier League in 2012 for a reported £32 million ($54 million) after inspiring Lille to the 2011 French Ligue 1 title.

Degryse, who scored twice in seven appearances at the 1990 and 1994 FIFA World Cups, said Hazard needs a wake up call from time to time to be shaken out of complacency.

"It is time for him to produce a good performance, on which he leaves his imprint. We have been waiting a long time for this. We have the right to expect this of a lad who is as talented as he is. If he doesn't feel concerned about this he has to give way to somebody else," said Degryse.

While Wilmots has dismissed the concerns of Degryse and others, saying that he expected Hazard to be on top form for Saturday's friendly with Tunisia, he did add that he would drop the player if he does not perform.

"He (Hazard) has my full support," said Wilmots, who guided Belgium to their first World Cup finals since 2002.

"He needs matches to get into the rhythm. However, there can be no doubt about his ability or form when one reflects on how he played for Chelsea last season. That said, if he plays badly I will not hesitate to replace him."

One theory being mooted is that Hazard has been distracted by talk of a transfer to French champions Paris Saint Germain, who have already bought his Chelsea team-mate David Luiz.

The 45-year-old Belgium coach, who played at four World Cup finals, is having none of that, saying: "I can tell you that the players are focused on anything but possible transfers."

"If I was still a player, I would put everything else to bed and wait for the end of the World Cup. In any case there are people (agents) paid to look after such matters."

Hazard's father and business manager, Thierry, supported Wilmots and said: "I read every day things that are not true. Eden asked of me one thing: that he be allowed to concentrate solely on the World Cup.

"As regards his future, there will be nothing about that during the tournament. Eden is ready to have an outstanding World Cup."

Belgium's first outing at the finals will be against Algeria on 17 June.