Manchester United have been approached by representatives of several managers believing that Erik ten Hag could be removed from his post before the start of next season, sources have told ESPN.

Ten Hag is under pressure following the 3-1 derby defeat to Manchester City on Sunday which left his team sixth on the Premier League table.

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The Dutchman has been told that securing Champions League football is vital to the club's aim of investing in the squad this summer while also meeting profit and sustainability requirements, but the result at the Etihad has seen United slip 11 points behind Aston Villa in fourth place with 11 games to play.

Ten Hag has been fully involved in planning for the summer -- both in terms of identifying transfer targets and organising the pre-season tour of the United States -- but a source has told ESPN the 54-year-old has been given no formal guarantee by new minority owner Sir Jim Ratcliffe or his team that he will be in charge next season.

It has prompted approaches from out-of-work managers and others who are currently in jobs to find out whether there will be a vacancy.

United, according to sources, have taken on board information about what different coaches have planned for the future, and what other interest there is in acquiring their services, but there have been no formal discussions with any candidates.

ESPN has contacted Man United for comment.

Liverpool, Bayern Munich and Barcelona are all looking for new managers for next season and, according to sources, are currently weighing up options.

Ratcliffe's team, headed by Sir David Brailsford and Jean-Claude Blanc, are still finalising the details of the new structure at Old Trafford, which will determine what profile of manager they want to take charge of first-team affairs.

Omar Berrada has been hired from Manchester City as the new CEO while Dan Ashworth is on gardening leave from Newcastle United amid interest in making him the new sporting director.

Ten Hag has a contract until 2025 and, when asked about his meetings with Ratcliffe, has said the 71-year-old British billionaire "believes in me."

Following back-to-back Premier League defeats to Fulham and City, Ten Hag is facing a crucial run of fixtures with a home game against Everton on Saturday followed by a FA Cup quarterfinal against Liverpool on March 17.

Liverpool's visit to Old Trafford is followed by the March international break with United next in action against Brentford on March 30.