Bartley, a £1 million summer signing from Arsenal, has only appeared once this term after suffering a thigh injury in training in September.
But the 21-year-old joined the senior squad this week as Michael Laudrup's charges prepare for Sunday's home clash with Liverpool.
But in an injury blow, fellow young defender Situ has suffered a ruptured Achilles playing for the U21s and has been ruled out for the rest of the season.
The 20-year-old suffered the injury in the loss to Cardiff and had to be replaced after 50 minutes.
Situ has been a regular for the U21s side since joining from Lens last year but has yet to make a senior appearance for the Swans.