Ole Gunnar Solskjaer has reportedly given his executive vice-chairman a deadline to sign Bruno Fernandes.
United are interested in the Portuguese attacking midfielder, but the move has slowed down in the past couple of weeks.
According to Record in Portugal, Solskjaer has spoken to Ed Woodward and laid out his deadline for having the Fernandes transfer completed.
The source claims that Solskjaer wants the move done by July 1, before preseason starts at Carrington.
Bruno's agent Miguel Pinho has reportedly been to England to speak with Tottenham, United and other teams.
But no club is willing to pay the €70 million Sporting want for their top talent.