Frank Lampard put Willian's future in the hands of Chelsea officials but hopes the in-form winger will be rewarded with a new contract.
Brazil international Willian has so far made a compelling case for an extension to his existing deal, which expires at the end of the season.
The 31-year-old assisted Tammy Abraham's opener in the weekend win over Crystal Palace and has scored in victories against Brighton and Hove Albion, Lille and Burnley this term.
His performances have eased the pressure on the younger members of Lampard's squad and the Blues boss made his appreciation clear following Saturday's 2-0 triumph at Stamford Bridge.
But he also admitted the final decision on fresh terms will not be his to make.
"The word isn't 'no-brainer' because I can't get involved in the money. That's up to the club to do," Lampard said.
"But everyone sees how much I'm relying on him and picking him and, in what he is producing, I love him at this football club. So there's my answer.
"I know his qualities from playing with him but when I looked at Willy over the last couple of years, he was in and out of the team. You're not sure, from the outside [what's happening]. I want to see him happy.
"Willy is a happy, easygoing lad who loves his football and that was the first thing I said to him at the start of the season.
"I saw him being huge in the way I wanted to play. Naturally, on the ball, we all know his ability to go by [markers] one-v-one and shift people and cross or get shots away.
"But his off-the-ball work is an outstanding example for Callum Hudson-Odoi, for Christian Pulisic, for other young players who think the only part of the game is going by people, crossing or shooting."
Lampard continued: "He does the other side brilliantly with absolute humility. He's been a joy and one of the experienced players who is helping the young boys."
Willian recently confirmed Chelsea turned down an offer for his services from Barcelona in 2018.