Despite Aarons appearing certain for a move, Championship table-toppers Norwich won't budge on their valuation.
And this decision could lead to United prioritising other investments.
The Daily Express says club chiefs may deem a £35m outlay on Aarons 'unnecessary' - choosing to target a new striker and centre-back instead.
The Red Devils already forked out £50m for Aaron Wan-Bissaka in 2019, and also have talented prospect Brandon Williams in reserve.
Sevilla defender Jules Kounde has emerged as a serious target, although club chiefs may also be reluctant to match his £68m release clause.