Jose Mourinho has urged Manchester United executive vice-chairman Ed Woodward to help him complete their third summer signing "as soon as possible".
The Red Devils have so far secured deals for two players in the ongoing window. Victor Lindelof was the first new face to arrive at Old Trafford from Benfica. Romelu Lukaku followed him as the striker completed a £75m ($97.4m) move to United from Everton.
Lindelof and Lukaku have been part of the 20-time English champions' first pre-season training session in the United States. The Belgium international scored twice in three friendly fixtures, including the opener in his side's 2-0 victory over Manchester City.
The Portuguese tactician has earlier suggested that he is looking to bring in four players this summer. The United manager stressed that he would be happy with only three new additions, but wants the third signing to be done quickly.
"When I look to the team and when I look to Lukaku, Lindelof, I would like my squad to be here, my whole squad," Mourinho was quoted as saying by United's official website.
"If you manage to get one more player, I am not even crying for two, but if we can get one player as soon as possible because you can see the way Lindelof and Lukaku are in the team, with the understanding of the players — for example, Paul Pogba's pass for Lukaku, the way he waited for support."
United still have to face Champions League and La Liga winners Real Madrid and their league rivals Barcelona in the United States. Mourinho remains unaware if the Red Devils' third signing will be able to face either of the two Spanish clubs.
"I don't know, I don't know. I am not in control of that. The credit of Lukaku and Lindelof to be here on time, the credit is not mine, it is Ed Woodward and his team," the former Real and Chelsea manager stressed.
"I thank him for that fantastic work to bring us two very important players for us. But we need a bit more when you see the other teams in the Premier League, like Man City, Liverpool and West Ham, the way they get players, good players, important players.
"The champions have bought three fantastic experienced players. I am thinking about West Ham for the first match of the Premier League. They have got Joe Hart, Chicharito and Arnautovic. It looks like they are playing to win the Premier League too. The teams are fantastic in the market. I am waiting for a bit more."