Manchester United Football Formation
Lineup (4-2-3-1)
De Gea · A Valencia · Shaw · Jones · McNair · Blind · Herrera · Fellaini · Di Maria · Rooney · FalcaoSince it is away match, yet against team with good attacking midfielders but defensively bad it is better to have two box to box players (Herrera and Fellaini) while keeping Blind covering the back four. RVP form is below average it is better to use Falcoa as his strength and tricks will be more than enough to overcome shaky gunners defence..
Playing Di Maria as more attacking midfielder than winger will give him more space to show his talent, especially if we keep in mind that Arsenal have average defensive midfielders.
If Arsenal play with Sanchez and Walcott, then A Valencia is better than Rafael, while Shaw needs to be in his on day to stop Walcott. Herrera and Blind can help in this regard.