Baleba is currently recovering from an ankle ligament injury suffered during Brighton's pre-season victory over Strasbourg earlier this month. The issue is expected to keep him sidelined for the opening weeks of the campaign.
Manchester United completed a deal worth £70 million for the Cameroon international, consisting of £65 million guaranteed and a further £5 million in add-ons. Baleba is set to sign a five-year contract with an option for an additional year.
The 22-year-old could potentially make his competitive debut around the middle of September, with United scheduled to host Manchester City on September 13 before travelling to face Fulham at Craven Cottage on September 20.
However, if Baleba is not sufficiently recovered for either fixture, his debut could be delayed until October. A three-week international break follows the Fulham match, providing the midfielder with additional time to complete his rehabilitation and become accustomed to his new surroundings.
His availability could also depend on whether he is selected for international duty with Cameroon during that period.
Major addition to United's midfield
Baleba's arrival represents another significant step in Manchester United's midfield rebuild under manager Michael Carrick.
The midfielder becomes United's third midfield signing of the summer, following the arrivals of Youri Tielemans from Aston Villa and Andrey Santos from Chelsea.
United had identified Baleba as a long-term target and previously attempted to sign him before Brighton's valuation made a deal difficult. The club eventually returned this summer and reached an agreement for a substantially lower fee.
The Cameroonian is expected to provide greater defensive strength, energy and ball-winning ability in the centre of the pitch, with his arrival particularly important following Casemiro's departure and Manuel Ugarte's injury problems.
For now, United supporters will have to wait before seeing their latest midfield signing in competitive action. If his rehabilitation progresses as expected, however, Baleba could be ready to make his long-awaited debut during a crucial run of fixtures in September.
Should he miss those matches, the international break could offer the midfielder valuable additional recovery time before he is introduced to the United team in October.
