"We didn't play well, apart from the last 10 minutes. The subs brought a bit of freshness, but perhaps the Russian defence was also pretty tired by then," Hazard told FIFA.com.
"Personally speaking, I feel good. I've been trying to make a difference, and often I end up doing that at the end of matches – that proves that I feel fresh."
Belgium play their final fixture in Group H on Thursday when they take on South Korea.