#3 Calum Chambers
Most of the people would be surprised to see Calum Chambers on this list, but there is no denying that the 24-year-old can put in a shift whenever required. He can play at center back, right back and as a defensive midfielder and his versatility can be a huge help for Arsenal next season.
With Unai Emery having a very limited budget this summer, bringing back Chambers and integrating him into the first team will be the right decision. Despite his previous loan spell at Middlesbrough ending in relegation and with Fulham also set to be relegated at the end of this season, Chambers has a ton of experience in the Premier League and if given a chance he can definitely impress at Arsenal next season.
Let's not forget, Calum Chambers was regarded as a top prospect when Arsenal signed him from Southampton way back in 2014. With the Englishman still only 24, he can still achieve all that he wanted when he initially joined Arsenal and if Emery feels he cannot get anything out of him, Chambers needs to sold this summer so that Arsenal can generate more money to spend on transfers.