The Japan international immediately won over the Emirates faithful when he arrived at the club from Bologna in 2021, succeeding the long-serving Hector Bellerin at right-back.
Tomiyasu impressed with his versatility and defensive capabilities to become a mainstay of Mikel Arteta's setup when fully fit, scoring two goals and providing six assists in 83 games.
The 25-year-old ended the 2023-24 campaign as Arteta's first-choice left-back, scoring the equaliser in Arsenal's 2-1 win over Everton on the final day of the season, but fitness issues have plagued him throughout his Gunners career.
The defender has never completed more than 22 games in a Premier League campaign and has missed 40 matches for club and country over the past three seasons, a number that will increase in the coming weeks.
Tomiyasu 'attracting interest' from Saudi Arabia
Tomiyasu was unavailable for all of Arsenal's pre-season due to a fresh knee problem, which will sideline him for the first portion of the Premier League campaign ahead of a possible return in September.
However, the 25-year-old may not even be around in North London by the time he has healed, as FootballTransfers claims that Arsenal would be willing to let him depart in the next couple of weeks if they receive an acceptable offer.
A return to Bologna was supposedly mooted while Arsenal were in discussions to sign Riccardo Calafiori, but the sell-on clause disputes involving Basel and Roma meant that idea was a non-starter.
Teams in the Saudi Pro League are supposedly interested in Tomiyasu, who only extended his Arsenal deal back in March, although his new terms are due to run out in the summer of 2026; he was not given a long-term agreement due to his injury problems.
Tomiyasu's latest knee concern could potentially jeopardise his chances of sealing an exit from North London, but Arteta is well-stocked in defence should the Gunners part ways with their £15.9m man.
Tomiyasu to be leapfrogged by academy product?
While Tomiyasu was in the recovery room in pre-season, Oleksandr Zinchenko often held the fort at left-back, while Calafiori also came on for his debut in that position in the Emirates Cup.
In the dying embers of that 2-0 win over Lyon, the Italy international shifted to a central role as 17-year-old academy graduate Myles Lewis-Skelly saw out the game at left-back, a position he has been gaining experience in over the summer.
Lewis-Skelly has traditionally played as a defensive midfielder during the embryonic stages of his career, but there is a feeling among Arsenal staff that the teenager could be an intriguing option in defence this season.
Even if Arsenal do not promote Lewis-Skelly just yet, all of Calafiori, Zinchenko and Jurrien Timber can play at left-back, as can Jakub Kiwior, although the Poland international's future is up in the air too.
Therefore, the Arsenal board could be forgiven for entertaining bids for Tomiyasu due to his abysmal fitness record, as they could easily still make a small profit on the £15.9m they paid for him, although a good chunk of Gooners would still be unhappy to see him leave.