Clive Allen's side will take on the winners of the northern section in a game on a yet to be confirmed date and staged by the northern victors.
United top the section at the moment by six points from Villa following this week's round of matches, but the midlands side do have two games in hand on the leaders. Middlesbrough are two points behind Villa having played a game more.
United have two games remaining, one against title rivals Villa on April 22 and the other against Liverpool on April 30. Villa's other fixtures are against Wolves, Liverpool and concluding against Leeds on April 27.
Should United win their two games they will be crowned champions and head into the play-off.
It looks like being between Manchester United and Aston Villa when it comes to who will provide our opposition in the Barclays Premiership Reserve League play-off.