Speaking on beIN SPORTS, Wenger said: "I believe it shows a new trend in the game that there is no transfer [fee], for the big big players; they go all at the end of their contract because the wages are so high.
"If you want to buy Marcel [Desailly] now, you have to pay him so much money that you can't afford the transfer fee anymore so what do they do?
"They say two years before the end of a contract: 'We want to buy you, we'll give you these wages, and we will try to make an offer. If it doesn't work, we will come back next year and if it doesn't work we'll take you for free', it's what they did with [Kylian] Mbappe.
"Real Madrid approached Alexander-Arnold a long, long time ago."