The Black Cats' under-21s, who could include former Pilgrims' loanees Liam Agnew, David Ferguson and Joel Dixon, arrive following United's clashes against Norwich City, Aston Villa and Nottingham Forest.
United boss Dennis Greene is expected to continue his assessment of trialists, with Danny Meadows and Michael Hollingworth potential starters against Sunderland.
The Jakemans (Town End) Stand will be closed for this fixture.