The Brazil international's current deal at Stamford Bridge is due to expire later this month and as it stands, he will be leaving Frank Lampard's side at the end of the current season.
The speculation surrounding the 31-year-old's future has gathered pace in recent days, and a recent report claimed that Barca had offered Willian a three-year deal to make the move to Camp Nou.
The South American has scored 11 times and registered nine assists in 47 appearances for the Blues this term, and it would certainly be a loss for the capital giants if he were to move on.
Here, Sports Mole looks at how Barca could line up with Willian.
Lautaro Martinez, meanwhile, is believed to be the club's leading target in the final third of the field, and the Spanish giants are said to be working on a player-plus-cash deal for the Inter Milan forward.
Willian has largely operated as a right-sided attacker this season, but Lionel Messi's presence means that the Chelsea attacker could line up on the left if he makes the move this summer.
Antoine Griezmann has struggled to impress since arriving from Atletico Madrid, and Willian would provide another genuine option in the final third, potentially forming a dangerous front three with Martinez and Messi.
Willian's versatility makes him even more attractive for the Catalan giants, and there would also be the option of moving him out to the right if Martinez does not arrive, while being part of a front three with Messi and Luis Suarez is another alternative as Barca look to wrestle the La Liga title back from Real Madrid.