Manchester United boss Louis van Gaal admitted his squad could look different by next week amid reports of bids being received for Javier Hernandez.
It has been claimed that Juventus and Valencia have both made offers for the 26-year-old Mexico striker.
United have not commented but Van Gaal, speaking at a press conference to unveil record signing Angel di Maria, did suggest further transfer activity is likely before Monday's deadline.
In addition to possible departures, United have also been linked with further new signings with Juventus star Arturo Vidal and Sporting Lisbon's William Carvalho the subject of speculation.
Van Gaal said: "I cannot say anything about that because it raises the price.
"The club shall comment when the time is there to announce it. We cannot react on every rumour.
"Also players shall go in the meantime. I had a conversation after lunch with the players and I said maybe after this weekend we shall have another group because players shall go away and others shall come in."
United have already spent £131.7million since the end of last season with Luke Shaw, Ander Herrera and Marcos Rojo their other main signings in addition to £59.7million Di Maria.
If Hernandez is sold, there could be implications for the future of another striker at United, Danny Welbeck, who is also thought to be the subject of interest from other clubs.
Van Gaal has promoted 18-year-old James Wilson to the first-team squad but selling both Hernandez and Welbeck would leave Wayne Rooney and Robin van Persie as the only senior forwards.
Hernandez joined United in 2010 from Guadalajara and has been a consistent scorer throughout his four years at the club, although not a regular starter.