#3 Virgil van Dijk
As usual, Laurent Koscielny has been performing consistently for the Gunners when he has been fit so far this season. And with Nacho Monreal perfectly adapting to his role on the left side of a back three, Virgil van Dijk would have made a fantastic trio at the back for the Gunners.
However, Arsenal chose not to buy the Southampton centre-back. With the Dutchman unwilling to stay at St Mary’s and Liverpool being categorically ignored by the Saints this past summer, it set up perfectly for the Gunners to swoop in and sign the centre-back, who is the sort of player Arsenal fans have wanted for years. But it seems Wenger chose to neglect the chance to sign him.
He is a commanding centre-back who is also very intelligent and good on the ball. With the inexperience of Rob Holding, the age of Per Mertesacker and the patchy performances of Shkodran Mustafi, van Dijk could have been the ideal player to solve Arsenal's conundrum at the back. Even though both Koscielny and Monreal are very good in the air, they lack the aerial threat that the 26-year-old would bring with his size.
Additionally, as mentioned, Van Dijk is very good on the ball, meaning he would not only fit in at Arsenal but potentially any club in the world.
Deciding not to go for the Dutchman in the summer could come back to haunt Arsenal with lots of top clubs being eager to snap up van Dijk next summer.