Ricksen is suffering from motor neurone disease and has previously revealed he intends to spend his final days in St Andrew's Hospice in Airdrie, North Lanarkshire.
The video, posted on a Twitter account called "Ricksen my friend/pauline", shows the Dutchman in a hospice bed with his computer-generated voice calling for supporters to turn out for his final public appearance for a "night to remember" .
"Hello, I'm having a special night on the 28th," he said.
"Since it's getting very difficult for me, this will be my final night.
"Come and make this a night to remember.
"Hopefully see you soon, Fernando."
The same account is advertising "An Evening with Fernando Ricksen",a fundrasier at GoGlasgow Urban Hotel on June 28 with his former Rangers team-mate Marvin Andrews also due to attend.
The video post was retweeted by Ricksen's close friend and biographer, Vincent De Vries.
The former Zenit St Petersburg player set up the Fernando Ricksen Foundation in 2016, raising money to fight MND, which attacks the nerves that control movement so muscles no longer work.
Ricksen, who made more than 250 appearances for Rangers between 2000 and 2006, revealed he had the terminal illness in 2013.
Mr de Vries, who regularly sends messages on Mr Rickman's behalf, clarified exactly what the footballer meant by his video message on Monday afternoon.
He quoted the footballer saying: "I would like to emphasise on the fact that June 28th will be my final public appearance.
"In other words: I do NOT have the intention to make it my final day.
"I will continue fighting, the rest of the battling is just going to happen out of the limelight."