Mourinho, who was appointed on a three-year deal last week, is believed to have begun assessing his squad.
Reports have claimed that the former Chelsea boss is planning to offload Blind because he does not possess the physicality to marshal the defence.
Also, Mourinho is reportedly ready to sell Juan Mata for a second time, having sanctioned the Spaniard's move to United in January 2014 while he was manager of Chelsea.
Despite the speculation, Blind has insisted that he will "work hard" for his place at Old Trafford.
"I am looking forward to working with Mourinho," Blind told NOS. "We will have to wait and see whether anything changes for me. I will just give my all and work hard. Mourinho is a manager who has achieved a lot and I am keen to work with him.
"I might not be as big as Pepe, but I think I have shown in the Premier League that I can hold my own defensively. We conceded the fewest goals in the Premier League and I think we got the most clean sheets.
"That's something to be proud of. I played nearly every game and that is a good feeling. You might be looking for a certain statement, but I will just give my all under Mourinho."
Blind was bought by former United manager Louis van Gaal from Ajax for £13.8m in the summer of 2014.