Plagued by injuries this season, Humphreys has been battling with an Achilles problem in recent weeks and was unable to play a role in the team last week as had been planned.
But the injury eased significantly this week and on Thursday morning he got the green light to play in his final match for Ulster when Cardiff Blues are the visitors to Ravenhill for the last Magners League match of the season on Friday.
The former Irish international who made 72 competitive appearances for his country, and is Ulster's most capped player with 163 after tonight, is delighted to be able to take a final bow at the ground he has simple lit up over an Ulster career which started in September 1994.
"With the injuries I have suffered this season I did not think it would happen. I am looking forward to running out one more time."
Meanwhile, on www.ulsterugby.com, Humphreys said thank you to his fans.
"....I just want to thank all the supporters for being there through the rainy nights at Ravenhill, the away trips and for all the overwhelming encouragement over the years. Ulster have experienced highs and lows during my playing career and I feel that I have been so lucky to be part of the good times as well as the bad.
"All week people have been asking what my favourite memory of Ravenhill is and I can't put my finger on one particular moment or game, but I know I will never forget the atmosphere on Friday nights at Ravenhill and the sheer excitement of the big games."
"No doubt, I will see you next year when I will be cheering on the lads from the other side of the fence with you, the supporters."
n Tickets for tonight's game will be available on the gate.