Fabio Vieira's Arsenal shirt number has been revealed after his transfer from FC Porto was confirmed on Tuesday.
The 22-year-old joins the Gunners on a long-term contract and will likely provide depth for the likes of Martin Odegaard and Emile Smith Rowe while staking a claim for a starting place.
The Portugal Under-21 international makes the switch for a fee that could rise to €40m (£34.3m) with add-ons.
Now Vieira has signed on the dotted line, attention has turned to the shirt number he will don at the Emirates Stadium next season.
An Arsenal club statement read: "Fabio will wear the number 21 shirt and join up with his new team mates soon for pre-season training.
"Everyone at Arsenal welcomes Fabio to the club."
The number 21 isn't exactly steeped in history at Arsenal. Previous incumbents include Calum Chambers, Lukasz Fabianski, Jermaine Pennant and Luis Boa Morte.
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Vieira - whose name will no doubt be popular with the Arsenal fanbase - enjoyed a breakthrough season in 2021/22 despite making just 15 starts.
The Portugal Under-21 international netted seven times and provided an impressive 16 assists in all competitions, including a hot streak between January and February where he laid on seven goals in five league games on the way to winning the Primeira Liga title.
FC Porto confirmed on Friday morning that they had agreed an initial €35m fee with Arsenal, with that sum potentially rising to €40m with add-ons. 90min understands that Vieira had an active €50m release clause but the Gunners were able to negotiate a deal for less.
Source : 90min