I presume Eden Hazard meant this in a more general sense when he was talking with French TV recently. I think Chelsea fans, by and large, will need a bit more convincing than a few good performances at Euro 2016 that Eden Hazard is back and working towards recovering his previous skills and capacities.
"I hope to return to top form. I know that if I have a good Euros, my bad season will be forgotten."
Hazard's worst season in a Chelsea shirt, and probably his whole career, has also been (not coincidentally) dotted by several fairly significant injuries, which have limited him greatly in the second half of the season. Just when he looked like he was starting to play better, around November or so, he got hip-checked by Jamie Vardy and that knock has been bothering him ever since. Along the way, he also picked up a groin injury that kept him out for most of January.
But, he finally notched a couple league goals last weekend and was looking a bit more threatening, in general, than he has most of the season.
"I am at 80-85 per cent of my abilities. Physical fitness comes with games."
-Eden Hazard; source: Canal+ via FourFourTwo
With Hazard recently committing his future to Chelsea, we can only hope that he does indeed have a good summer and a good Euros and then follows that up with an even better 2016-17 season.