Gourcuff had been in danger of missing out, having made only 13 league appearances for Lyon this season due to injury, and has not represented his country since March 2011. Meanwhile, Yanga-Mbiwa, who celebrated his 23rd birthday on Tuesday, took the place of Tottenham Hotspur centre-back Younes Kaboul, who was forced to drop out of the squad due to a patellar tendon injury.
"Younes is out of the EURO," said Blanc on Eurosport. "He has a fairly significant injury to his knee, the patellar tendon, that's been troubling him for quite a while."
Blanc had previously unveiled a 12-man list of players playing overseas on 9 May. Yanga-Mbiwa's inclusion came at the expense of Mamadou Sakho, who lost his place in the Paris Saint-Germain starting line-up following the arrival of Italian coach Carlo Ancelotti in December.
Sakho's team-mate Blaise Matuidi also received a call-up, but there was no place for PSG striker Kevin Gameiro or Lyon's Bafetimbi Gomis. Marseille striker Loic Remy was granted a place in the squad despite having sustained a thigh injury on Sunday that is likely to keep him out of action for up to four weeks.
France were drawn alongside England, Sweden and co-hosts Ukraine in Group D at the EURO 2012 and begin their campaign against the English in Donetsk on 11 June. Blanc must announce his final 23-man squad by 29 May.
Preliminary France squad
Goalkeepers: Cedric Carrasso (Bordeaux), Hugo Lloris (Lyon), Steve Mandanda (Marseille)
Defenders: Gael Clichy (Manchester City/ENG), Mathieu Debuchy (Lille), Patrice Evra (Manchester United/ENG), Laurent Koscielny (Arsenal/ENG), Philippe Mexes (AC Milan/ITA), Adil Rami (Valencia/ESP), Anthony Reveillere (Lyon), Mapou Yanga-Mbiwa (Montpellier)
Midfielders: Yohan Cabaye (Newcastle United/ENG), Alou Diarra (Marseille), Yoann Gourcuff (Lyon), Florent Malouda (Chelsea/ENG), Marvin Martin (Sochaux), Blaise Matuidi (Paris Saint-Germain), Yann M'Vila (Rennes), Samir Nasri (Manchester City/ENG), Franck Ribery (Bayern Munich/GER)
Forwards: Hatem Ben Arfa (Newcastle United/ENG), Karim Benzema (Real Madrid/ESP), Olivier Giroud (Montpellier), Jeremy Menez (Paris Saint-Germain), Loic Remy (Marseille), Mathieu Valbuena (Marseille)