Arsenal boss Arsene Wenger has said his side "cannot afford to lose players" as he voiced concerns that injury problems could derail their current fine run.
The Gunners lost at home to Aston Villa on the opening day of the season, but have won every game they have played since to go to the top of the Premier League table.
They defeated Paolo Di Canio’s Sunderland 3-1 on Saturday, but saw striker Olivier Giroud, who scored the opening goal, limp off with a knee problem and are also without Santi Cazorla, who has an ankle injury.
Wenger said Cazorla will miss Wednesday's Champions League clash with Marseille and, with Lukas Podolski also on the casualty list, told the BBC: "We score because we have a good game, lively with a lot of energy, we are dynamic in our game, and have a lot of belief as well.
"But we are still short now. With the injuries we have, we cannot afford now to lose players."
Arsenal were boosted by a fine debut from club record signing Mesut Ozil against the Black Cats, with the Germany international's touch and vision setting up Giroud and creating a string of other opportunities.
The North Londoners, who missed three clear chances through Theo Walcott, could have had the game won by half-time but had to work for the points after a Craig Gardner penalty hauled Sunderland level.
Two goals from the rejuvenated Aaron Ramsey decided the match, and Wenger said: "We had plenty of chances in the first half -- we had an outstanding first half. In the second half, Sunderland played very well with much more energy.
"But we found the mental resources again to win the game and were much more clinical in the second half."
Information from the Press Association was used in this report.