Sanchez is expected to complete a move to the Emirates Stadium after Barcelona accepted a £32 million offer for the Chile star, with Arsenal manager Arsene Wenger making the 25-year-old his priority signing.
Debuchy has undergone a medical ahead of finalising a £8m move from Newcastle to replace the departed Bacary Sagna - who joined Manchester City on a free transfer.
Edu spent four seasons at Arsenal under Wenger, winning two titles and three FA Cups, and the 36-year-old feels the addition of Sanchez and Debuchy can boost the Gunners' trophy ambitions.
"Arsenal are still in my heart and I still follow Arsene Wenger. I have a big relationship with that club," he told talkSPORT.
"If they sign them [Alexis Sanchez and Mathieu Debuchy] of course Arsene Wenger is very clever.
"Everybody knows he is good at signing players, particularly young ones, and they can give good things to Arsenal and make them better and stronger as they look to win the Premier League."