Arsene Wenger's side have been the victims of a cup shock at the hands of Bradford City already this season and need a result against Brighton to keep alive their most realistic chance of winning silverware.
He told the club's official website: "It will be tough there. They played really well against Newcastle in the third round and were the better team.
"They like to play some good football as well, so it will be a very interesting game.
"There is something about the FA Cup, it has great tradition in England and the fact you play the final at Wembley makes it special."
Arteta is unavailable for today's tie as he edges closer to a first-team return from a calf strain.