Mustafi, a Germany international with 12 caps to his name, expressed delight on his £35m move to the Emirates, having described his time with Valencia as "turbulent." Los Che struggled to avoid relegation from La Liga this season, following a management crisis that saw three managers - including ex-England assistant coach and former Manchester United defender Gary Neville, come and go.     

"It's not easy to cope with [Valencia's crisis] as a player. The past season was demanding, very demanding. The club wanted to qualify for Champions League, yet all of a sudden we were only four points above the line," said Mustafi in an ESPN interview. The center-back is seen to bolster Arsenal's back line, with the likes of Per Mertesacker and Gabriel Paulista barely managing to keep it intact in recent times.

Perez, originally slated to move to Everton, was the subject of Arsenal's late interest as talks with the Toffees collapsed. For £17m, he brings great value for his combined total of 25 goals scored and assisted for Deportivo in La Liga last season.

"He's not only a goalscorer, he's a guy who combines well with partners, who can give a final ball and makes good runs," said manager Arsene Wenger on the 27-year old striker in a Mirror interview.

Perez's stints in several clubs across Europe ultimately led to his rise in Deportivo, where he emerged as its top goalscorer in a striker role last season. He's set to play alongside striker Olivier Giroud or winger Alexis Sanchez in a secondary striker role - one that's initially offered to Jamie Vardy, who ultimately chose to stay with Premier League champions Leicester City.