The Blues manager was full of praise for the winger who only misses out through injury ahead of his side's away Champions League clash
Frank Lampard thinks Chelsea will survive the loss of Willian even if he joins a rival like Arsenal having already coped with the sale of Eden Hazard to Real Madrid last summer for £88 million ($115m).
Willian is understood to be in advance talks with Arsenal over a three-year deal having only been offered a two-year contract to stay at Stamford Bridge with no room for negotiation.
Chelsea look set to lose the 31-year-old but Lampard was clear that Willian only didn't travel due to a minor Achilles injury ahead of Saturday's away match with Bayern Munich.
Lampard spoke of his great relationship with his former team-mate and the player he now manages but expects his side to cope with him leaving in the near future.
"It does not matter if there's a disappointment from any party, in this situation," Lampard said in Munich on Zoom video conference. "He remains our player at the moment. He was injured for the cup final and injured for tomorrow and he would have given everything to play in those game.
"I know Willian well, I have seen him. He has carried this injury a little bit in the latter part of the restart. In terms of being disappointed, certainly as a club we have done everything we can to explain [the situation] to Willian.
"Mine and his relationship is very close and I would have no feeling of disappointment if he does move on. He is a fantastic man and a fantastic player. I think he will feel like that about Chelsea. I will leave him to say his own words.
"But I don’t want anyone to try to find a negative attitude. The club have acted very well in this as well. If he moves on I personally will wish him well. I think he [would] leave a hole as a player who has been here for I think seven seasons, being part of successful teams.
"When I came in and we had a lot of issues in terms of younger players, players back from loan, transitional elements to the group, Willian as the one you looked at and relied on in terms of his experience and quality. He has shown me that all year. He has his own decisions to make.
"We as a club will always want to move forward, no matter what. Eden Hazard left last year; the club continues to work in a forward direction which I think we have in many ways. That remains the same, whatever player leaves the club.
"When a player is out of contract, they have the freedom and the right to play wherever they want. You have to understand that if they stay in the league and it is a player of Willian’s quality, for instance, then they will go and contribute to that team.
"We have to accept that and move on. I have no problems with that."
The 31-year-old first joined Chelsea in 2013 from Anzhi and has since taken a third-captain role at the club and team-mate Antonio Rudiger, who previously explained that Willian helped him settle in London, admitted that he would be missed.
"He is own man and he makes decisions for himself," Rudiger said after Lampard's press conference. "I don’t know what the situation is yet but if he goes it will be a huge loss for us. Especially after the restart people could see he was very important for us."
The Blues face a difficult task on Saturday night as they try to overturn a 3-0 first leg home defeat against a Bayern Munich side that have won their last 17 domestic games and who were crowned Bundesliga champions in July.