Lookman, who was in the starting 11 was replaced in the 63rd minute.
Prass opened the scoring for Sturm Graz in the 13th minute before Muriel made it 1-1 on 34 minutes.
Atalanta went 2-1 ahead as Muriel grabbed his second goal after scoring from the penalty spot seven minutes added time in the first half.
Sturm Graz were reduced to 10 men following Hierlanders sending off on 52 minutes.
Despite having a player sent off Wlodarczyk equalised for Sturm Graz from the penalty spot on 80 minutes.
Atalanta lead the group and have seven points from three games played.
In Group C, Rangers forced Sparta Prague to a 0-0 draw.
Cyriel Dessers could not replicate his weekends scoring form as he fired blanks.
Leon Balogun was not in action for Rangers as he did not even make the squad for the trip.
Dessers, who spearheaded Rangers attack, was replaced by Danilo in the 74th minute.
The draw means Rangers are bottom on four points in the group.
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