Arsène Wenger says Arsenal were punished for chasing the game at Chelsea on Saturday.
The Gunners fell behind to two early goals after being caught out by the home side's swift counter-attacks at Stamford Bridge. A third goal, scored from the penalty spot after Kieran Gibbs was mistakenly sent off, ended the game as a contest.
"It looked like we missed the start of our game and were caught on the counter-attacking," Wenger told Arsenal Player.
When we were down to 10 men, down to 3-0, it became of course an impossible task
"We had a desire to accept to play and to go forward, but we were caught on the break. After that of course the game became very long because down to 10 men, down to 3-0, it became of course an impossible task.
"We tried to come back and we always continue to have a go and I give credit to the players for that at least. We tried to score a goal but it was too difficult. When you have to attack with 10 men and you're down 3-0, you know you have more chances to concede another goal. That's what happened."
Alex Oxlade-Chamberlain escaped punishment for giving away a penalty at Chelsea but Wenger expects the England international to be available to face Swansea City.
"The sending off is simple," said Wenger. "If the red card is rescinded we will have Chamberlain available.
"I believe there are two situations. First, mistaken identity so Gibbs will normally be available, which is the minimum you can expect. After that the second decision depends on whether Chamberlain deserves a red card or not.
"There the rules are quite clear. If the ball will go in the back of the net it is a red card. If the ball will miss the target it is not a red card, so I believe that this red card will go as well and Chamberlain will be available."Copyright 2015 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source