Their third qualifying round second leg was postponed in midweek following the tragic death of the Spanish side's 22-year-old defender Antonio Puerta.
Also in Group H will be 1986 winners Steaua Bucharest from Romania, and making up the group are Slavia Prague.
Edelman told Sky Sports News: "I think it's the first time we have never played one of the teams we have we have been drawn against.
"We have played in Prague quite a bit over the last few years, Bucharest we have never been to and it's going to be a new challenge for us, we have played a lot in Athens and Sevilla, of course, had a great run in the UEFA Cup and have done extremely well in that competition.
"I think they are all tough. The thing about the Champions League is it's an exciting competition but also a very challenging one.
"We have a very good young team full of enthusiasm. There is great team morale and we are confident we can have a great season and in Arsene (Wenger) pulling together enormous talent. We feel very positive about that."