Manchester United boss Louis van Gaal says they'll be working the summer market with intensity.

Van Gaal is anticipating a busy summer of ins and outs in the transfer market, admitting that squad improvements are needed if the Reds are to challenge Chelsea for the league crown next season.

He told MUTV: "It's always like that [busy in the summer]. I don't think you have to keep the whole selection because when you purchase other players, you get another stimulus in the group and you need that.

"Our selection is out of balance and we have managed to be fourth in the league but we have to manage to be the champions. That's why we have to take care first of the balance of the selection but also to improve our selection because we want to be the champions. It shall be a rough summer I think for a lot of players but I think a top club like Manchester United have to do that."