Jamie Soward and Dallin Watene-Zelezniak with Panthers member Jacob King.

Jamie Soward and Dallin Watene-Zelezniak took time in their off-season break this week to visit Nepean Hospital and surprise Panthers member Jacob King.

Jacob suffers from a rare immune deficiency condition and for the last 11 years has undergone monthly blood transfusions in the Children's Ward at Nepean Hospital.

While the treatments will continue for the rest of his life, Jacob turned 16 on Wednesday, meaning his transfusions will now take place in the main part of the hospital.

To mark his final treatment in the Children's Ward, the nurses presented the passionate Panthers member with a special birthday cake while Soward and Watene-Zelezniak hand-delivered a 2015 Heritage Jersey.

Jacob, who rarely misses a Panthers home game, said he was already counting down the days to the 2016 season and was particularly excited to see former AFL player Josh Hall in action.

"We've watched Jacob grow up on the ward and it really has been a privilege for us to care for him each month," Nepean Hospital Children's Ward Nurse Unit Manager Shannan Waddups said.

"We're so grateful to have the support of the Penrith Panthers in arranging this surprise."