Spanish striker Perez, who has been likened to former target Jamie Vardy, is on the brink of completing a £17million move to the Emirates.
And the long-running pursuit of Mustafi is also finally close to an end with the German centre-back expected to arrive for £35m.
Wenger added: “Perez is a late developer, he played in a different position. He moved centrally in a successful way. I think he has good link up qualities, good quality of receptions, good finishing qualities.
“Mustafi was Valencia’s captain. If we get it done we get what we wanted.”
With only one point from their two Premier League games, Arsenal can ill-afford to fall further behind their rivals ahead of today’s trip to Watford.
Wenger added: “We need a first win after our game at Leicester.
“We have shot ourselves in the foot so we have to respond very quickly. When you look at other teams they are making points.”