Manchester United are considering making further additions to their squad before the new Premier League season.
The Red Devils have signed Mason Mount and Andre Onana, while a deal for Rasmus Hojlund is nearly concluded.
The likes of Dean Henderson, Harry Maguire, Fred and Scott McTominay could be sold, while manager Erik ten Hag admitted more may arrive.
"We are always looking for better quality," Ten Hag said to reporters.
"So if you want to be at United you have to match a really high standard and when we find the opportunities to get better we have to do it. Because everyone is expecting the best from us.
"So we also have to raise the bar there but it's also very important that the players understand we believe in them - believe in their potential, believe in their personalities. Because team spirit, togetherness, the fight together, the social connection, the relationships has to be really good among footballers. It's a team sport and when we are unified we are stronger.
"Football evolves. A club evolves and there come moments where you renew your squad but you have to do it in a strategic way. It doesn't say that the players didn't contribute to Man United because it would be really disrespectful if you approach it in that way.
"I'm totally involved [in the sales strategy] but you have seen all the investments which other clubs are making and you can't compete in the Premier League for the top positions when you don't invest in your squad.
"You see the market but I can do nothing for it or anyone else at United. It's a choice, if you want to compete you have to invest."
