The 100,000-capacity venue was placed in the second phase of the Trafford Wharfside Strategic Masterplan Consultation Draft, produced by Trafford Council.
Phase two covers the period from 2031 to 2035, while the first phase runs from 2025 to 2030 and does not include the stadium.
That means United supporters could potentially have to wait until the latter part of the 2031-35 period before entering the new ground.
The project has already experienced several changes to its expected schedule. Sir Jim Ratcliffe announced in March 2025 that United would construct a new stadium instead of redeveloping Old Trafford, initially suggesting the project could be finished within five years.
Ratcliffe said at the time that he would prefer to spend five years on the project rather than 10, adding that he might not be around in a decade.
Subsequent reports pointed towards a possible 2030 completion, while Collette Roche, United's chief executive for New Stadium Development, later indicated during the summer that the venue could potentially open around 2032.
The latest planning indication therefore represents a further extension to the proposed timeline.