I'd be surprised if he did know after half a dozen pre-season games. How often is the team that starts the season the same as the team in round 10 or round 20?
Also, the idea of a "starting XI" is outdated in modern football. Big clubs have squads of 20-25 players of a similar level. There are obvious star players who you would expect to start many games when fit, but the days are long gone of having a squad like 2011-12 where there was basically 11+3 players used for most of the season.