The Brazil international is nearing the end of his sixth campaign at Stamford Bridge, but the playmaker has been linked with an exit over the past two years.
Barcelona are one of the clubs who have been monitoring any developments with the 30-year-old, and it appears that the Catalan giants may be ready to renew their interest.
According to The Sun, an offer in the region of £30m could be made during the next transfer window with Willian having just over a year left on his contract.
Chelsea may look to hold discussions with Willian over his future, but the player is unlikely to want to stay with the Blues unless he is offered more than a one-year extension.
Willian has contributed eight goals from 51 outings in all competitions during the current campaign.