Academy defender Marc Jurado and midfielder Omari Forson trained with the Manchester United first-team on Monday.
Right-back Jurado participated in the session with Aaron Wan-Bissaka not visible in the imagery that was released by United.
Fellow full-back Luke Shaw was also missing, having sat out two of the last three games. Shaw has not played since August 13 and is currently nursing a minor foot injury.
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Forson was also recalled to the training squad to likely offset the absence of Donny van de Beek, who has missed the last two matches through injury.
Senior United players were due at Old Trafford on Monday for a scheduled appearance, possibly a squad photo.
United have not arranged for a squad photocall at the stadium since 2015 when Louis van Gaal was manager. The squad photos in Jose Mourinho's three seasons were all photoshopped and United did not issue one during Ole Gunnar Solskjaer's tenure.
Jurado and Forson, both 18, participated in first-team training earlier this season. Figures at United downplay any academy promotions to the first-team as it is usually on a temporary basis.
Kobbie Mainoo, Tyler Fredricson and Charlie McNeill were called up to training on the eve of the Europa League tie against Real Sociedad last week. McNeill emerged for his debut a day before his 19th birthday and Fredricson was an unused substitute.
United signed Jurado from Barcelona's academy in 2020 and he started in their FA Youth Cup final win over Nottingham Forest in May.
Forson joined a year earlier from Tottenham's academy.
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