The Real Madrid forward has made just three appearances for the Spanish club since making his world-record move from Tottenham, and is currently sidelined by a thigh injury.
Wales boss Chris Coleman confirmed the 24-year-old would not feature in either of their final World Cup qualifiers, saying: "We have spoken to the doctor and we will be without him, but we said all along it is very tough for him to have had no pre-season and be thrown in at the deep end."
Coleman's captain Ashley Williams is also a fitness doubt due the ankle ligament injury which has kept him out of Swansea's recent run of fixtures.
But he is included, despite Swans' manager Michael Laudrup's pleas for him to be given the rest required to fully recover from his injury.
There is, however, no place for West Ham defender James Collins.
Coleman was critical of Collins after last month's defeat to Serbia, claiming he had turned down the chance to join up with the squad with Williams suspended and Sam Ricketts injured.
Collins insisted he would never turn his country down and that he had not received a message asking him to join up, but Coleman has clearly decided the player was in the wrong and has omitted him.