Limited to a bench role since the shock 2-1 defeat to relegation candidates Crystal Palace last month, the 29-year-old has started only half of his side's opening 12 Premier League matches in 2017-18. He recently admitted his desire to play more regularly amid renewed suggestions from the Sunday Express that he could be set to reunite with former manager Jose Mourinho, who is said to see him as a more consistent option than Anthony Martial.
Willian recently admitted that he did have contact with United during the latter stages of the summer transfer window, although apparently never came close to following midfield enforcer Nemanja Matic from Stamford Bridge to Old Trafford.
A return to his homeland has also been mooted, with the 49-cap Selecao international, who began his career with Corinthians before moving to Europe with Shakhtar Donetsk in 2007, now linked with a move to Sao Paulo rivals Palmeiras.
However, Willian has moved quickly to politely dispel those new rumours, telling journalists via Twitter that he has not held any talks with last year's Brazilian champions and harbours no desire to return home at this stage of his career.
Responding to reporter Sandro Barboza, he said: "Hi Sandro, how are you? Sorry, but I'm not negotiating with Palmeiras and my manager has not received any contact from the club. I have no plans to return to Brazil at this time. A hug."
A subsequent tweet to Juca Kfouri read: "Sorry, but I don't have the goal of returning to Brazil and never spoke, or my representative, with anyone at Palmeiras. This is nothing but speculation. A big hug."
Willian has made 199 appearances since famously snubbing Tottenham Hotspur to sign for London rivals Chelsea from Anzhi Makhachkala in a £30m ($39.7m) deal in August 2013 and will reach his double century if he features in the Champions League Group C tie against Azerbaijani competition debutants FK Qarabag in Baku on Wednesday afternoon (22 November).
Having already slipped behind Pedro and Eden Hazard in the pecking order, manager Antonio Conte's switch to a 3-5-2 formation that includes three central midfielders will presumably make it even more difficult for the player, who recently encouraged Chelsea to recall Ruben Loftus-Cheek from his season-long loan stint at Palace, to regain a regular starting berth.
French publication Le10 Sports suggested earlier this month that the Blues could even look to offload Willian when the transfer window reopens for business in January in order to fund a €30m deal for compatriot Lucas Moura, who has struggled for opportunities at Paris Saint-Germain under Unai Emery.
However, they were said to be hoping to sell him to a club in the Chinese Super League (CSL) rather than a domestic rival such as United.