While talking with the media ahead of the game on Friday, Lampard disclosed the Brazil international was carrying a knock, which saw him left out the FA Cup final against Arsenal last week.
Willian’s contract deal with the Blues expires after their European competition, with the 31-year-old close to signing for Arsenal.
Chelsea have done everything we can to try to keep Willian.
“I haven’t got an answer for you (if Willian will leave) first and foremost, because Willian remains our player at the moment.
“He’s injured for Saturday, and he was injured for the cup final. He would have given everything to play in those games.
“I know Willian well. I’ve seen him, he’s carried this injury a little bit from the latter part of the restart,” Lampard said.