Sources have told ESPN FC that United are interested in central defenders Jerome Boateng, Toby Alderweireld, Harry Maguire and Yerry Mina but Mourinho - who has said the season could be "difficult" if the squad is not bolstered - admitted at a news conference on Thursday he is not expecting any new arrivals.
This new deadline which closes before the season starts has really ramped up the pressure on these transfers which means we could see a whole host of panic buys as clubs look to add to their squad before the Premier League season starts this weekend.
Part of this can be explained by the fact one of the 20 Premier League clubs - Tottenham - saw no incomings, the first time this has happened since the summer transfer window was introduced in 2003.
"I'm not confident, I'm not confident and the market closes today so is time at least for me to stop thinking about the market because the market will be closed".
Left-back Joe Bryan secured a reported £7m switch from Bristol City after a strong season in the Championship and will hope to form a strong partnership with the highly rated Ryan Sessegnon, while Timothy Fosu-Mensah strengthens Fulham on the right side of defence following a loan departure from Manchester United.
"The information I have is no".
Mourinho revealed he will be without six senior players for the game against Leicester.More news: West Ham sign Arsenal's Lucas Perez and Fiorentina's Carlos Sanchez
"My view is that, first of all, it is hard for me to believe we finished second because when I listen, when I read - not much but sometimes I do - you [the media] are capable of making people that finish second look like they were relegated, and people who win nothing, finish below us, you make them look like serial winners".
"It is hard to believe that we finished second".
"Is hard for me to understand, to feel, to believe we finish second".
Mourinho heads into the Leicester match with a hefty injury list, including key midfielders Nemanja Matic and Ander Herrera, while a host of other stars of only recently returned from their break after World Cup duty.
Mourinho also needs to check on the fitness of those that returned late from the World Cup. "The list of injured players is an important list and, after training, I will speak with that group of [World Cup] players because everybody is different, physically and mentally, to see how they feel they are and to understand how they can help or not help".
Pre-season has clearly been a frustrating time for Mourinho, while a perceived lack of respect for leading his side to second spot last term has got under his skin.
"[Alexis is] more than ready but you can not have the players who arrived only last Monday after the World Cup semi-finals or final and three weeks' holiday".