Out-of-favour Arsenal midfielder Fabio Vieira has completed a season-long loan move to Primeira Liga giants Porto.

Vieira, who joined Arsenal from Porto two years ago in a £34m transfer, has largely struggled to make a significant impact during his time at the Emirates Stadium.

The Gunners have been relatively quiet in the transfer market this summer, with Riccardo Calafiori and Mikel Merino being their only significant signings so far.

The only other piece of business done was making David Raya's deal permanent after the Spaniard spent last season in North London on loan from Brentford.

While there are still a few days to get new deals over the line, Arsenal seem focused on offloading players on the periphery before making a final push to sign additional reinforcements.

Porto confirm Fabio Vieira arrival

Porto revealed via their official account on social media platform X that they have brought Vieira back on a loan deal for the 2024-25 season.

During his first stint with the club, the Portuguese international broke into the senior team in 2019 and went on to score 10 goals in 76 games.

The 24-year-old has been handed the number 10 jersey, which was recently vacated by Francisco Conceicao, who was allowed to move to Juventus on loan earlier this month.

It is understood that Vieira's loan agreement at Estadio do Dragao does not include an obligation for Porto to buy him at the end of the season.

Vieira made a total of 49 appearances for Arsenal since arriving at the Emirates, scoring three goals and providing nine assists in that time.

Rare clause included in Vieira loan agreement

Fabrizio Romano revealed that while Porto are under no obligation to buy Vieira at the end of his loan spell, the Gunners have included a rare penalty clause in the agreement.

It is understood that the clause will come into effect if the Portuguese giants do not play the 24-year-old in 50% of their matches following his arrival.

There is no mention of whether the player's appearances must be in the starting 11, though it is believed that failure to do so will result in a financial penalty.

While these types of terms are fairly rare, reports suggested that the Gunners included a similar type of clause in Eddie Nketiah's loan agreement with Leeds United back in 2018-19.

Vieira is the second player to depart Arsenal in the past 24 hours, following academy graduate Charlie Patino, who joined Spanish club Deportivo La Coruna on Monday.