Arsenal have named both Marquinhos and Matthew Smith in their senior 24-man squad for the 2022-23 Europa League.
The Gunners have been drawn against FC Zurich, Bodo/Glimt and PSV Eindhoven in Group A and will open their continental campaign against the Swiss champions on Thursday.
Mikel Arteta has quickly promoted former Sao Paulo youngster Marquinhos to the first team at Arsenal, in spite of the expectation that he would feature predominantly for the Under-21s or be sent out on loan.
Since scoring three goals and setting up one more in three Premier League 2 appearances, Marquinhos has been an unused substitute against Fulham, Aston Villa and Manchester United in the Premier League.
The 19-year-old is set to ply his trade in Europe this year after being handed a place in Arsenal's 24-man senior squad, where midfielder Smith also features.
The 21-year-old - who captains the club's youth team - is still waiting for his senior competitive debut for the Gunners 13 years after initially joining their academy.
Smith does have an FA Cup winners' medal to his name after being involved in the 2019-20 final squad, and he registered two assists in 43 League One games for Doncaster Rovers on loan last term.
With Smith now classed as a senior player, the Englishman - who was on the bench against Aston Villa - joins the likes of Marquinhos, William Saliba and Gabriel Martinelli in the 24-man squad.
UEFA rules permit players aged 21 or under who have been at a club for at least two years to be included on a team's B list - Martinelli fits this criteria but has been named in the senior squad.
Goalkeeper James Hillson also joins Matt Turner and Aaron Ramsdale in the 24-man party, with Estonia international Karl Hein expected to be among the B list players.
Bukayo Saka has not been included in the 24-man squad, but the England international is seemingly set to feature as part of the B list, while there are some other notable absentees for the Gunners.
Seventeen-year-old centre-back Reuell Walters impressed for the club in pre-season but will not be taking part in the Europa League group stage, and neither will highly-rated left-back Lino Sousa.
Sousa only joined the Gunners from West Bromwich Albion in January, while Walters has been at the club for less than two years, meaning that the pair cannot be included on the B list.
Arsenal head into their Europa League opener with Zurich at the top of the Premier League table and aiming to recover from Sunday's 3-1 loss to Manchester United at Old Trafford.
Arsenal squad:
Goalkeepers: Aaron Ramsdale, Matt Turner, James Hillson
Defenders: Ben White, Gabriel Magalhaes, William Saliba, Rob Holding, Cedric Soares, Takehiro Tomiyasu, Oleksandr Zinchenko, Kieran Tierney
Midfielders: Thomas Partey, Mohamed Elneny, Granit Xhaka, Albert Sambi Lokonga, Fabio Vieira, Martin Odegaard, Matt Smith
Attackers: Gabriel Jesus, Eddie Nketiah, Gabriel Martinelli, Emile Smith Rowe, Marquinhos, Reiss Nelson body check tags ::
