Except, he's really not.
"He's got all the gear on and I mistook him for one of my players today because he looks in good condition, he's testing well," coach Tana Umaga said, having watched him complete a "bronco" shuttle-run exercise the day before.
Legendary first-five Spencer - now aged 42 - guided the Aucklanders to their last Super Rugby triumph in 2003 before departing the franchise in 2005.
Arguably, they still haven't replaced him in the No.10 jumper.
But the flamboyant 35-cap All Black will return for one final roll of the dice in this weekend's Brisbane Tens, as the Blues' wild-card pick.
He admitted the event would present its own challenges on an aging body, despite keeping in good nick while coaching Japanese outfit Sanix Blues.
Nevertheless, he couldn't wait to get out there.
"Conditioning-wise and fitness-wise I'm fine, but it's taking that initial contact - which I never liked anyway," Spencer said with a grin.
An unrivalled entertainer on the rugby field, Spencer left Auckland after 96 Super Rugby games to head north and enjoy a fruitful stint with Northampton.
He rounded off his playing career in South Africa with the Lions.
But the Blues remained his first rugby love, and reigniting his relationship with the franchise was a key reason for his Tens return.
"Just to reconnect with the Blues and the club again after such a long period away, that's probably the main reason," Spencer said.
"I'm always up for a challenge."
With most of his All Blacks regulars absent, Umaga has called upon a youthful squad for the Tens, naming just two stars in Akira Ioane and George Moala.
The presence of Spencer would thus be beneficial.
"It's good to have him, he's a legend of our club," Umaga said.
"I've got no expectations, we'll just play it by ear - when he wants to go on, we'll put him on, and when he wants to go off, we'll take him off."