In the Premier League table, Aston Villa are placed 12th with 18 points from 15 games, while Brighton are sitting seventh with 21 points from 14 matches.
This will be the second friendly for Aston Villa this month. They were beaten 3-1 by Cardiff City last week.
Brighton & Hove Albion will host Aston Villa in an English Premier League fixture at the Falmer Stadium on Sunday.
Despite having 59% possession on Sunday, the Red Devils could only manage eight shots in total and just three were on target.
Aston Villa are placed 13th in the table and have 15 points from 14 matches. They will now hope to put together a good run of form under Emery.
Man United are sitting fifth in the table and have 23 points from 13 games. Meanwhile, Aston Villa have jumped to the 13th spot and have 15 points from 14 matches.
Ronaldo's most memorable outing came in a 4-0 win at Old Trafford in 2008, when he scored once and assisted the remaining three goals.
Sitting fifth in the Premier League table, Manchester United have 23 points from 12 games. They are just one point shy of fourth-placed Newcastle United.
Villa are currently placed 16th in the standings and are just one point above the relegation zone. They have lost three of their last four matches.
Grealish made the big move to the blue side of Manchester after more than seven years at Aston Villa to play under Pep Guardiola.