Arsenal are working on a mutual agreement to terminate Willian's contract before a free transfer to Brazilian club Corinthians.
The deal could save the Gunners millions of pounds as the Brazil midfielder still has two years left on a three-year contract, reported to be worth more than £200,000 a week.
Willian, 33, joined Arsenal from Chelsea on a free transfer last summer.
He made 25 league appearances last season but is yet to feature this term.
Before Arsenal's 5-0 defeat by Manchester City on Saturday, Gunners boss Mikel Arteta said he "didn't know" why Willian's time at the club had not been more successful.