No financial details were disclosed but British media said the fee for Mustafi was £35 million and Perez cost £17 million.

Mustafi has been at Valencia for the past two seasons while Perez joined Deportivo La Coruna in August 2015.

The 24-year-old defender, who is on international duty, began his career at Everton’s academy before moving on to Sampdoria.

“He is at the right age. He has good experience. He is a very focused player who can play with the ball as well,” manager Arsene Wenger told the club’s website (www.arsenal.com.).

“We have taken a great player.”

Perez netted 19 goals in all competitions for Deportivo last season including seven in as many games to equal the record of former Brazil striker Bebeto.

The 27-year-old started his career with Atletico Madrid before having spells at Rayo Vallecano, Ukrainian club Karpaty Lviv and PAOK Salonika.

Wenger said he would fit in well with Arsenal’s possession- based style.

“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, added the Frenchman.

“He’s got a good eye for goal and had an outstanding season last year.”

Arsenal, who tasted their first league victory of the season against Watford on Saturday, next play Southampton on Sept 10.