The 18-year-old winger has caught the eye of some of Europe’s top clubs having broken into Sporting’s first team this season.
Chelsea attempted to bring Bruma to West London last year but the Lisbon giants managed to tie him down with a new deal.
However, Bruma’s lawyer, Bebiano Gomes, says his deal expired at the end of last month, but the club have insisted there was a clause that triggered an automatic renewal, prompting an awkward court case to hold up any move.
Bayern are already believed to have made a £4 million bid to take Bruma to the Bundesliga, a £2 million rise on the bid Chelsea had previously tabled.
Bruma’s older brother, Buomesca, is already on the books at Fulham so Chelsea could have the upper hand as the two could be reunited in the English capital.
Armindo Tué Na Bangna, as his full name reads, has made eight appearances for the first team, scoring once, but he’s been heavily involved in the segunda team where he’s scored six times in 25 appearances.