Two different situations:
Probably AW made a mistake because sell him and buy an adequate replacement was the right way, but the chilean - despite it’s clear he wants to leave - doesn’t look a problem. No doubt about his effort.
Last July, when the team was in Australia, he talked about the potential new contract as an easy choice, his preference was to stay. Now everything is in doubt: his desire to sign a new contract is in doubt, if he is useful or not is in doubt.
Sincerely I was scared to see them leaving the club, but Lacazette, Kolasinac, the other players, showed which effort and desire to go forward.
I would love to see them out in January, replaced by other two players with the desire to fight for Arsenal and the qualities to be useful.