The Red Devils are still keen on adding the forward to their squad before the window slams shut on Monday night, with a prospective deal still on the table.
Dembele was unsure about whether he wanted to leave the Nou Camp and his preference previously was to stay and fight for his place.
However, Barcelona now look set to land former Man Utd flop Memphis Depay in a transfer that has been in the offing for more than two months.
Lyon star Depay is expected to completed a switch worth £25million plus add-ons, as he prepares to put pen to paper on a five-year deal that was agreed over nine weeks ago.
Journalist Fabrizio Romano claims Dembele will now be sold as a result, with United prime candidates to land his signature.
Spanish publication Sport claimed recently that Dembele snubbed the chance to move to Liverpool on loan, but the Premier League champions are not expected to be in the race on deadline day.
Manchester United are looking to plot their path back to the top. Ole Gunnar Solskjaer has already brought in Donny van de Beek but Jadon Sancho remains Manchester United’s number one target.
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United turned their attentions to the 23-year-old after failing in their pursuit of Jadon Sancho.
The Red Devils are interested in taking Dembele on loan and have so far refused to budge over £50m to sign him on a permanent basis.
Barca are looking to recoup as much of the initial £96.8m they paid Dortmund for the Frenchman in 2017, but could be willing to drop their asking price to offload him.
Dembele has proved to be a difficult player to have around, with several misdemeanours against his name previously, mainly through missing training or turning up late.
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His 2019/20 season was also hampered significantly by injury, as he made just nine appearances in all competitions for the Spanish club.
New boss Ronald Koeman was open to giving Dembele a fresh start but he is not considered among the regular starters.
Should United get a deal over the line, it could be one of three transfers they complete on the final day.
Full-back Alex Telles is due to arrive from Porto, while United are also set to sign free agent Edinson Cavani.
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