Belgium playmaker Eden Hazard insisted Monday he will improve as the World Cup advances.Hazard set up Divock Origi's late winning goal for the Red Devils against Russia on Sunday, a result that qualified Belgium for the knock-out stages.Even so, the Chelsea star, 23, has not been pleased with his own performances in the Group H matches."I haven't played well yet at this World Cup but I've made a difference and that's what the coach has asked of me," Hazard told a team press conference in Mogi das Cruzes."I understand that people expect a lot of me and I know I can do better."Hazard also created the winning goal for Dries Mertens in Belgium's 2-1 defeat of Algeria in their opening match."Making a difference twice at the end of a match shows that I'm fresh and that I feel good physically," added Hazard."But I hope the fans will see a better Eden Hazard than in the previous two games."Hazard gave himself an 11 out of 20 for his performance against Russia: "Two out of 10 for the first 80 minutes and nine out of 10 for the end," he stipulated.Meanwhile, centre-back Thomas Vermaelen could be fit again within a week, coach Marc Wilmots said."The scan showed Thomas Vermaelen has a hamstring strain. He's already started rehabilitation with the medical staff," said Wilmots."It's a strain. In six or seven days he'll be fit again and able to join the group. "If that's the case I'll definitely use him again in this World Cup."The Arsenal centre-back came off after just half an hour against Russia and will miss Belgium's final group match against South Korea in Sao Paulo on Thursday.