Rashford had struggled with a shoulder problem during the latter part of the 2020-21 season and played only a limited role with England during their run to the Euro 2020 final, where they lost to champions Italy.
“Following consultation between Marcus, the manager, club medical staff and specialists, Marcus will undergo surgery imminently to resolve his shoulder injury,” United said in a statement.
United gave no indication of the likely length of Rashford’s absence, but the BBC reported earlier this month that the 23-year-old is expected to be out for around 12 weeks and will miss the start of the Premier League season.
Rashford’s absence at the start of the campaign would be a huge blow for manager Ole Gunnar Solskjaer, with the Norwegian aiming to improve on last season’s second-place league finish.
United start their 2021-22 season on 14 August against Leeds United at Old Trafford.