Hazard fired the winning spot-kick as Chelsea edged out Eintracht Frankfurt 4-3 on penalties to book an all-English Europa League final against Arsenal, in what could prove his last act at Stamford Bridge.
The Belgium forward is still expected to join Real Madrid in a big-money move this summer, but his Brazilian team-mate Willian continues to hope otherwise.
Luka Jovic cancelled out Ruben Loftus-Cheek's strike to take Thursday's semi-final second leg into extra time before penalties had to separate the sides with the aggregate score level at 2-2 and one away goal apiece.
Asked if Hazard's decisive penalty could prove his last kick at Stamford Bridge, Willian replied: "I don't know, I don't think so.
"For me I hope he stays, but in football you never know. I think his head is here, to play for Chelsea.
"Then after he's finished the season maybe he can talk about his situation.
"I don't know anything about him leaving so for me I hope he can stay.
"He's very important, a special player, he's very important for us, he helps us a lot.
"And he's one of the best players in the world."
Chelsea captain Cesar Azpilicueta's missed penalty handed Eintracht the early advantage in the shoot-out, only for Kepa Arrizabalaga to pull off two fine saves.
And when Hazard buried his spot-kick, Chelsea had scraped their way into their first European final since the 2013 Europa League.
Hazard appears closer and closer to sealing his Madrid move, with his Chelsea contract expiring next summer and the Blues understood to be holding out for £100million to let him leave for Real.
The Belgium star said "In my mind I don't know yet" when asked if he had already played his last game at Stamford Bridge.
Hazard will bid to guide Chelsea past Arsenal to a sixth European title in Baku on May 29 whatever happens next term, with both major continental finals ending up as all-English affairs for the first time.
Chelsea boss Maurizio Sarri insisted the Blues would be worthy Europa League winners after a turbulent campaign that could end in success.
"We were in trouble three months ago and, here in England, if you're in trouble the level of opponents is very high and it's not easy to overcome difficulties," said Sarri.
"We were able to do it. So now we deserve to win a trophy."
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