Sydney FC could wrap up the A League minor premiership in the next week but star midfielder Luke Brattan has much more important things going on off the field.

This morning he’ll be shaving off his luscious locks in the Leukaemia Foundation’s World’s Greatest Shave… and he’s doing it for someone very close to his heart.

His younger sister Holli has been diagnosed with Mixed Phenotype Acute Leukaemia – a very rare type of blood cancer.

At just 23 years of age, Holli has spent months in hospital receiving chemotherapy and blood transfusions and has just had a bone marrow transplant.

Luke has already raised more than $20,000 and is hoping for much more when he shaves his head live on Channel Nine’s Today Extra this morning.

He says his “beautiful little sister” is an inspiration.

“She’s young and she’s strong, she’s definitely going to get through this!”

Click PLAY below to hear the full interview

CLICK HERE to donate to Luke’s fundraiser