Arsenal's squad appears stretched ahead of Wednesday's Carabao Cup quarter-final against north London rivals Tottenham, particularly defensively.
Defender Sead Kolasinac was a late withdrawal at St Mary's due to tightness in a thigh muscle, while right-back Hector Bellerin limped off with a calf problem and, according to Unai Emery, could miss "some weeks".
Defenders Sokratis Papastathopoulos and Shkodran Mustafi served one-match bans during Sunday's 3-2 loss on the south coast, with the latter doubtful to return for the Spurs cup tie because of a hamstring issue.
Centre-backs Rob Holding (knee) and Konstantinos Mavropanos (groin) are also on the sidelines.
All three of Saints' goals came from headers following the visitors' failure to deal with balls into the box.
Substitute Charlie Austin nodded the 85th-minute winner after Henrikh Mkhitaryan twice cancelled out goals from Danny Ings.
Emery, whose side have scored 37 times in the top flight and conceded 23, knows Arsenal must tighten up at the back.
"It's true we need to improve and concede less chances to the opposition," he said.
"We are scoring a lot but we are also conceding a lot, it's more than we want for our objective."
Scroll through Arsenal's full injury and suspension list in the gallery above...
