Ralf Rangnick has allegedly agreed to become the English club's interim manager for the remainder of the season, with the Red Devils then planning to target Pochettino as Ole Gunnar Solskjaer's long-term replacement.
The Argentine has a contract with Paris Saint-Germain until June 2023, though, and according to the Daily Mail, Man United have identified Ten Hag as an alternative target if a move for Pochettino fails.
The report claims that Ten Hag is interested in becoming the Premier League outfit's new head coach next summer, and Ajax would be prepared to let the 51-year-old leave.
The Dutchman has won two Eredivisie titles and two KNVB Cups during his time at the Johan Cruyff Arena, taking charge of 186 matches for the club since arriving in December 2017.
Michael Carrick will again lead Man United against Chelsea in the Premier League on Sunday, and the former midfielder will be looking to make it back-to-back successes at the helm, having overseen a 2-0 victory over Villarreal in the Champions League on Tuesday.