Song and Gervinho return from domestic suspension while youngsters Frimpong and Jenkinson continue after impressing against Liverpool.
Robin van Persie, who was suspended for the first leg last week, also starts in Italy.
Johan Djourou returns from a hamstring strain and partners Thomas Vermaelen at centre half.
Team in full: Szczesny, Jenkinson, Vermaelen, Djourou, Sagna, Song, Frimpong, Ramsey, Walcott, Gervinho, Van Persie.
Subs: Fabianski, Traore, Miquel, Rosicky, Oxlade-Chamberlain, Arshavin, Chamakh.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 24 Aug 2011