Manchester United boss Louis van Gaal has warned his squad that they face a rough summer as he eyes new players in the upcoming transfer window, Mirror reports.

During a speech at United’s award ceremony, Van Gaal said that in order to challenge for the title the club need to evolve, signifying a potential summer overhaul.

WANT MORE? >> Manchester United transfer news | Latest transfer news

“It's always like that," he said.

“I don't think you have to keep the whole selection [squad], because when you purchase other players, you get another stimulus in the group also, and that you need.

“I think also our selection is unbalanced. We have managed to be fourth in the league, but we have to manage to be the champions.

“That is why we have to take care of the balance of the selection, but also to improve our selection, because we want to be champions.

“So it shall be a rough summer for a lot of players, but I think a top club like Manchester United has to do that."

Red Devils goalkeeper David de Gea won the player of the season accolade at the event, however the Spain number one is expected to leave and join Real Madrid this summer.

But De Gea isn’t the only player linked with an exit, as Radamel Falcao, Robin van Persie, and Jonny Evans are all on the chopping block ahead of the 2015-2016 campaign.

Falcao has failed to justify his massive wage bill while on loan from Monaco, scoring just four league goals all season.

Meanwhile Van Persie and Evans have struggled with form and injuries, and could both leave to make room for summer reinforcements.

United are targeting the likes of Edinson Cavani and Mats Hummels as potential replacements, players that would justify Van Gaal’s need to evolve the squad.

[ad_pod id='ffc-video' align='center']