United had seven players involved in the final weekend of the World Cup with Romelu Lukaku, Marouane Fellaini, Phil Jones, Marcus Rashford, Ashley Young, Jesse Lingard and Paul Pogba representing the club and set to return late.
"Unavailable is [Sergio] Romero - he had a surgery after his injury before the World Cup".
While United and other Premier League teams in England will not be able to bring in players after August 9, they can still sell players to other teams around Europe until August 31.
Manchester United start the new Premier League campaign with a clash against Leicester City on Friday night.
The club did not consider any other centre-back on Jose Mourinho's wishlist of a similar value.
Three early points and a ideal start to the season.
"Manchester United fans are uncomfortable with what they're watching", Nicholas told Sky Sports.
"They need to get a centre-back in".
"But he is saying about judging in November; I think when you look at Manchester City's start, they look really invigorated already".
The match at Old Trafford kicks off at 8pm BST on Friday, with live coverage available in the United Kingdom on Sky Sports Premier League and Sky Sports Main Event.
At Old Trafford, Leicester City have lost on seven of their last eight visits in the league (D1), scoring a total of just three goals in that period.
"If you compare with Europe, you are at a complete disadvantage and it does not help the clubs in the Premier League", Pochettino said on Spurs' tour of the United States.
The Red Devils are the clear favourites to win this one, but the Foxes will be confident of springing a surprise at the Theatre of Dreams.
Claude Puel's realistic aim will be to have Leicester finish in the top half of the Premier League this season. "That's just not like this football club".
Contrary to current belief though, Mourinho has been fairly successful in the transfer window in his two years at Manchester United and has built perhaps the strongest side Old Trafford has seen since Sir Alex Ferguson left the club in 2013.