#4 Rob Holding
Rob Holding is one of many youth prospects Arsenal have had who have failed to make the cut. Although he spent much of the season out with a knee injury, the games he has been involved in have been nothing special, which has prompted fans to wonder if the team perhaps needs a world-class player in that role now.
With a market value of around £10 million, Holding would be ideal for a club in the Premier League, but, realistically, a team in the bottom half. This is exactly why fans are so frustrated with their club; the longer they have players of Holding's calibre in the first team, the longer they'll struggle to surpass the fourth position each year.
How he's still on the books at Arsenal is a question that dumbfounds most people, but the Gunners seem desperate to see out Holding's time at the club, hoping that one day he'll realise the potential they always thought he had -- they could be waiting for some time, however.