Southampton manager Ronald Koeman says he will look to strengthen his squad in the January transfer window after losing three key players to injury.
Saints ended the 1-0 loss to Arsenal with 10 men, having used all three substitutes when Toby Alderweireld suffered a hamstring injury.
"A lot of midfielders are injured and that creates a lot of problems," Koeman told BBC Radio Solent.
"I will speak to the board about what we need and what we would like to do."
Belgian defender Alderweireld, who was playing out of position in midfield after an earlier injury to Jack Cork, is expected to be out for up to three weeks,
Cork went off in the first half with an ankle injury, while French midfielder Morgan Schneiderlin is also out with a hip injury and both players will miss the visit of Manchester United on Monday.
"This is the hardest league because you can lose against everybody," said Koeman.
"You have to be prepared every game and you can't play on 70%. You have to be 100% and that's difficult for us, because we need everybody.
"Everybody needs to be fit and we don't have the numbers and players that the big teams have, and that's difficult."
Southampton's position in the Premier League's top four is coming under pressure after a second successive defeat, but Koeman said he would not attach too much significance to a match his side lost in the 89th minute when down to 10 men.
"In my opinion the difference between the two sides is that we were unlucky after the third change," said the Dutchman.
"To play the last 10 minutes with 11 versus 10 made the difference.
"We had ball position and dominated the game but when it was 11 against 10 they smelled the opportunity to win the game. That moment was the difference."