Arsenal threw away a first-half to lead to crash out of the Carabao Cup at the third-round stage following a 3-1 defeat to Brighton on Wednesday night.
The Gunners may be flying at the top of the Premier League, but this was perhaps another example as to why Mikel Arteta will need to strengthen in the January transfer if his side are to continue to challenge Manchester City for the title.
Arteta rang the changes for the game, with William Saliba the only player included in the starting XI who started the 1-0 win at Chelsea on Sunday.
And several of the Gunners' second string failed to take their opportunity to impress, with the likes of Fabio Vieira, Marquinhos and Sambi Lokonga struggling to make any sort of impression.
Reiss Nelson and Eddie Nketiah did catch the eye and it was the two academy products who combined for Nketiah to open the scoring in the first half.
But a mistake from 20-year-old goalkeeper Karl Hein on his debut gifted Brighton an equaliser through a Danny Welbeck penalty and second half goals from Kaoru Mitoma and Tariq Lamptey gave the visitors a deserved win.