Hundreds of Celtic fans chanted his name as Keane’s arrival on loan from Tottenham, with just seconds to spare before the transfer deadline, became real right in front of their eyes.
Revered for years by those who follow the Irish team around the world, and used to life as a hero at places like Wolves, Coventry, Leeds and Spurs, Keane had still seen nothing quite like it.
One fan even texted the BBC late on Monday night to suggest that January 31 had overtaken Christmas Day as the greatest day on his calendar!
Celtic fans like their heroes. We’ve known that as long as we’ve known about football itself, and the fact that Keane will wear Larsson’s jersey for the remainder of the season tells a tale all of its own.
When Dermot Desmond funded this big move for Keane -- he will cost the Bhoys over $100,000 a week in wages -- he knew his club was crying out for a savior.
With Rangers some 10 points clear at the top of the table the jury is very much out on new manager Tony Mowbray, who has yet to decide on his best Celtic team after seven months in the job.
Attendances are down at Parkhead, the fans were losing faith in the team, and their gaffer and Desmond needed to do something very special to put the wow factor back into the green half of Glasgow.
Keane, like Larsson before him and Gazza at Rangers, will provide the missing wow factor, so much so that the bookies have already slashed the odds on Celtic catching Rangers and winning the title.
If they qualify for the Champions League then my belief is that Robbie Keane will stay at Celtic, probably for the rest of his career, never mind next season.
He’s not in this game for the money anymore. He has more money than any kid growing up in Dublin ever dreamed of.
He does need the adulation, though. That’s why the 41st goal of his international career meant so much to Robbie in Paris last November, why defeat hurt him so badly that night.
This Keane will be a hero in Glasgow, without a shadow of a doubt. He will score goals for fun, he will tease and torment defenders and he will scare the living daylights out of a Rangers side probably already counting their title chickens.
If he succeeds in the three months between now and the end of his initial loan spell then Robbie will earn something else that has been largely missing throughout his career -- a winner’s medal.
That’s why he’s in Glasgow. That’s why he wants to be the new Henrik Larsson.
The old one, by the way, believes this new number seven will be a hit.
“It is fantastic news for Celtic to get a striker of his quality,” said Larsson on Tuesday. “From what I understand he is a great fan of Celtic as well and that’s very important. He will know how important it is for the fans to play well. I’m sure he's going to do well up there.”
Incidentally, there was one remark from our current Keano on Monday night that may just have been directed at a previous incarnation of the terrace chant.
“I didn’t want to come here when I was 34 and my career washed up,” Robbie Keane told the Scottish media.
I wonder who he was referring to? Not our Roy!