Manchester United manager Louis van Gaal insists the club's recruitment drive is not over, and that he hopes to fill two more positions before the transfer window shuts.
In a frenetic three days this week United addressed questions about their midfield with the signings of Bastian Schweinsteiger from Bayern Munich and Morgan Schneiderlin from Southampton.
Matteo Darmian also arrived from Torino, addressing the problem area of right-back.
United are expected to bring in another centre-half before the summer is over, while the departures of Robin van Persie and Radamel Falcao – in addition to doubts over the future of Javier Hernandez – leave the Premier League side short up front.
And when asked if more players will be arriving at Old Trafford in the coming weeks, van Gaal told MUTV: "I hope so. No, we are not finished yet, I think.
"It is what I have said already in many press conferences. We need a balance in the selection and I think we still need to improve at least two positions.
"But we shall only buy when the player can give a contribution to our level. And, of course, that is in the eyes of our staff, but I have to have confidence that he can cope with the rhythm of the Premier League."
United remain heavily linked with a move for Real Madrid defender Sergio Ramos, with Spanish daily AS claiming on Thursday the club are preparing a final bid of €60m (£41.8m, $65.3m) for the Spain international.
Nicolas Otamendi is also linked and appears poised to leave Valencia after he was left out of the club's new kit launch.
United are also likely to be in the market for another goalkeeper, whatever happens with David de Gea in the coming days. While the custodian remains linked with Real Madrid, back-up sticksman Victor Valdes is to leave Old Trafford after just six months, with Van Gaal pointing to his failure to follow his philosophy as the reason for the breakdown in their relationship.