Greece international Tzolis had developed into one of Europe most sought after players on the back of scoring 42 goals in two seasons at Club Brugge.
The 24-year-old grabbed the opportunity put forward by the defending Premier League champions despite the ongoing rumours over a blockbuster bid incoming from them for Real Madrid superstar Vinicius Junior.
Trossard's exit has freed up a space on the left side of Arsenal's attack, with Gabriel Martinelli also potentially moving on, and that powered Mikel Arteta's determination to wrap up a deal for Tzolis.
Rumours over Vini Jr are not impacting Arsenal's newest recruit, who bagged a debut goal in the preseason win over Girona, and he's ready to go straight in into the team once the league campaign begins later this month.
"I'm only thinking how I can improve and settle as fast as possible. I have an opportunity to train directly with the team from the beginning of the season, to play the friendlies and then the official games.
"This is a chance to play directly from the beginning - and then it's up to me to show the qualities and what I can bring in the team. I'm pretty confident I will show it in the next games."
Arsenal take on Real Betis in Dublin in their next preseason outing on August 5th at the Aviva Stadium.