Lokomotiv Moscow have reportedly still not granted permission for Ralf Rangnick to leave his role as head of sports and development at the Russian club.
Manchester United are believed to have agreed a deal with the 63-year-old to become the team's interim manager for the remainder of the 2021-22 campaign.
Rangnick, who last managed RB Leipzig between July 2018 and June 2019, is then expected to take on a two-year consultancy role at Old Trafford.
A recent report claimed that the 20-time English champions were hopeful of announcing the German's arrival within the next 48 hours.
However, according to The Sun, Man United are now sweating on the appointment, as Lokomotiv are yet to grant Rangnick permission to leave his role at the club.
Michael Carrick led Man United to a 2-0 win over Villarreal in the Champions League on Tuesday night and will again be in charge for Sunday's Premier League clash with Chelsea.
