Belgium have won their two pre-tournament friendlies ahead of Brazil 2014 - thrashing Luxembourg 5-1 before a 2-0 win over Sweden - with Hazard playing 123 minutes over the two matches.
The Chelsea attacking midfielder scored Belgium's second goal against Sweden on May 31 but Degryse argued Hazard, who received criticism from Jose Mourinho over his defensive work-rate towards the end of last season, must improve or be dropped.
"He has to work harder defensively," said Degryse, who scored 23 goals in 63 appearances for Belgium from 1984-96.
"Against Sweden he switched off several times, just like he did in the (UEFA) Champions League for Chelsea against Atletico Madrid.
"If that doesn't change (Belgium coach Marc) Wilmots will have to resolve it by dropping him.
"Hazard is the type of player that sometimes needs a kick up the a***."
In the Champions League semi-finals last season, Mourinho claimed Hazard was to blame for two of Atletico Madrid's goals at Stamford Bridge as the Belgian let Juanfran get forward to provide assists.
Mourinho claimed Hazard is not a team player.
"He's not the kind of player ready to sacrifice himself 100 per cent for the team and his mates. I'm not happy," the Portuguese manager said in early May.
Belgium will play Tunisia in their final warm-up match on Saturday before opening their first World Cup finals campaign in 12 years against Group H opponents Algeria on June 17.
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