Former Pompey star Chris Kamara is appealing to Blues fans to help him raise money for Marie Curie Cancer Care.
The charity has been adopted by the Football League this season.
Kamara has backed the partnership in memory of his mother, who was cared for by Marie Curie nurses at home before she died.
He is asking fans to join his Home or Away Challenge and raise 500,000 for the charity.
Fans can either do the home challenge - cycling from Land's End to John O'Groats - or join a team of Football League managers and supporters trekking up Mount Kilimanjaro on the away leg.
Both challenges take place in June.
He said: 'My perfect Christmas list would include a fan from every Football League club taking up a challenge and joining me to raise money for this fantastic cause.
'Marie Curie nurses will be working in every Football League community across the country this Christmas, giving terminally ill people the choice of being looked after at home, surrounded by their family and friends.
'I want to rally support across Football League clubs to ensure that Marie Curie can continue to deliver free nursing care to people who want to be looked after at home.'
To find out how to take part, see portsmouthfc.co.uk
Those who can't take up a challenge can make a 3 donation to Marie Curie Cancer Care by texting 'GOAL' and 'Portsmouth' to 70300.