#5 Lucas Perez

Lucas Perez had just come off the back of an excellent season with Deportivo La Coruna when he joined Arsenal in 2016 for a fee of around £17 million.
He scored 17 goals in his final season there, but appeared just 11 times for Arsenal in the Premier League, scoring just the single goal, away at Bournemouth.
Because of those struggles, he returned to Deportivo on loan last year. He has returned to North London this summer, but there are a lot of attacking options available to Unai Emery, so Perez is unlikely to be a regular in the first team.
There will be clubs out there who will want a player like Perez in their squad, and it would be good for Arsenal to sell, as it will generate funds as well as give them some room to manoeuvre as far as wages are concerned.