Speculation mounted that the France forward was Camp Nou bound after he missed training without permission on Thursday.
Borussia Dortmund have confirmed that they have extended Ousmane Dembele's suspension "until further notice".
The decision to extend the suspension was taken after a meeting on Saturday night between Bosz, chief executive Hans-Joachim Watzke and sporting director Michael Zorc.
"Our focus now is on preparation for the Bundesliga opening match in Wolfsburg [on 19 August]".
"Ousmane Dembele, of course, has the opportunity to do individual training off the track".
His unauthorised absence came after Barca had a bid rejected for the France global, who has been earmarked by the Liga powerhouse to replace Neymar following the Brazil star's world-record €222million transfer to Paris Saint-Germain this month.
Dortmund rejected a €100m (£90m) offer from Barcelona for Dembele in midweek and he was fined and suspended for missing training until after Saturday's German Cup game for the defending champions against Rielasingen.
While Dembele has been strongly linked with a move to Barca, Liverpool midfielder Philippe Coutinho is also said to be interesting Ernesto Valverde's side and has reportedly handed in a transfer request.