Rangnick, who was manager of sports and development at Russian club Lokomotiv Moscow, had to wait for a work permit to begin his role at Old Trafford..
The Norwegian boss is under intense pressure after a 5-0 home thumping by Liverpool and a one-sided 2-0 defeat at the hands of Manchester City on Saturday.
Solskjaer admitted one good game would not silence United's doubters and challenged his team to prove in Italy that they could perform consistently.
Jose Mourinho has criticized the atmosphere at "quiet" Old Trafford on Alexis Sanchez's home debut.
Manchester United manager Jose Mourinho is confident Romelu Lukaku's problems in front of goal will come to an end -- just as soon as he secures a new boot deal.
Manchester United manager Jose Mourinho believes he deserves credit for not complaining more about Paul Pogba's injury problems and those affecting the rest of his squad.