Selena Gomez and Francia Raisa are ''like sisters''.

The 25-year-old star revealed on Thursday (14.09.17) that she underwent a kidney transplant over the summer, after her best friend agreed to be her donor, and a source close to the duo has claimed Francia wouldn't have hesitated in making the decision.

The insider explained: ''Francia and Selena are like sisters. There's a group of girls who have always stuck close to Selena.

''Her inner circle is very tight and everyone protects Selena. Francia comes from a big family ... Selena is like a sister to her.''

Selena revealed in a heartfelt Instagram post she needed the transplant due to her Lupus, a chronic condition that can damage any part of the body.

But according to the insider, Francia would have been equally kind towards any of her close friends.

The source explained to Us Weekly magazine: ''Selena didn't ask Francia to be tested as a match - Francia is the kind of person who would offer to do that for any one of her friends.''

The celebrity duo also made a conscious effort to keep details of the surgery under wraps.

The insider shared: ''Francia told a few people in her inner circle that she was donating one of her kidneys, but no one knew who it was for.

''A lot of people in their inner circle knew that Francia was undergoing surgery but really didn't ask too many questions.''

And Francia - who is, perhaps, best known for her roles in 'Bring It On: All or Nothing' and 'The Secret Life of the American Teenager' - has already made a complete recovery from the procedure.

The source added: ''Francia is totally fine now, she's back to normal. Francia lives a very healthy lifestyle and she's busy with work. The recovery time for her was very quick.''