Leandro Trossard will not be available to play for Arsenal in their crucial match against Manchester United on Sunday, after the Gunners failed to register him with the Premier League in time.
New registrations of players have to be completed by midday the day before a round of matches, and, with matchday 21 starting on Saturday, that therefore means Arsenal would have needed to register the Belgian by midday on Friday.
Despite agreeing both personal terms and a fee potentially rising to £27 million with Brighton on Thursday, however, Arsenal still didn't manage to complete the signing of Trossard until after the deadline.
This is due to Trossard still having to complete a medical, which, if done thoroughly, can take an extensive period of time. Wout Weghorst suffered the same fate for Manchester United last week, signing for the club after the 12pm deadline and therefore missing the game against Manchester City.
The cut-price deal reflects Trossard being out of contract at the end of the season. Arsenal agreed personal terms first.
Trossard's agent recently slammed Seagulls gaffer Roberto De Zerbi, too, over his treatment of the attacker, saying the Belgian won't be staying at the club.
The 28-year-old adds much-needed depth to the Gunners' ranks and becomes the second Belgian on the books, with Albert Sambi Lokonga already at the club.
Arsenal head into Sunday's clash against Manchester United top of the table, eight points ahead of their opponents and five clear of Manchester City in second place - though they do have a game in hand.
The Gunners have only lost once in the league this season, at Old Trafford against Manchester United. United ran out 3-1 winners on that day in September, with Antony scoring on his debut and Marcus Rashford grabbing two goals.
Arsenal will still be confident without Trossard, too, with it unlikely the Belgian would've even started. Indeed, Granit Xhaka and Martin Odegaard have occupied the more attacking midfield positions this season, while Gabriel Martinelli and Bukayo Saka are in no danger of losing their starting spots on the wing.
