Frank Lampard expects Willian to show what he's capable of during Chelsea's FA Cup final clash against Arsenal.
The 31-year-old could be playing in his final domestic game for the club after seven years with his contract set to expire at the end of the season.
Willian has been ever-present in Lampard's team this season which has seen him record 11 goals and nine assists in 47 appearances in all competitions.
Lampard confirmed that the Brazilian will return to the side after being absent against Wolves, but he will be assessed again to see if he is fit enough to start.
But despite his ongoing contract situation, Lampard expects Willian to maintain his professionalism which he has shown throughout the season on Saturday at Wembley.
"Yes, because I’ve known Willian for many years now as a player and now as his coach. And if anyone wants to see the mentality of him, it’s been shown since restart.
"He’s been fantastic for us, he’s been fantastic this season. He’s shown the right attitude.
"So I would expect nothing less than he’s shown already, and that’s Willian for you.”
Chelsea were tipped to be the new favourites to keep hold of the winger beyond this summer, and it was reported that the Blues could agree a deal with him by the end of the week.
But Willian has contract offers from Barcelona and Inter Miami as well as Chelsea, but won't make a decision on his future until after the FA Cup final.