The new boss will be contemplating his selection for Sunday's Premier League encounter at Ipswich Town, with much focus on the formation he will deploy.
However, Ruben told us in his exclusive interview last week: "A lot of people now talk about the 3-4-3 and the 4-3-3 and all that stuff. But, when I think as a player or as a team-mate of Manchester United, it is not a system or formation, it's like the character of the players, the way they see the club.
"So we have to focus on that before the everything of how we play, how we press.