When the Greek striker leaves, only Scott Brown, Lukasz Zaluska and James Forrest will have been at Parkhead for longer.
And, of course, this is Mulgrew's second stint in the Hoops, having been sold by Gordon Strachan in 2006.
So, overall, he has more years' service for the club than anyone in the dressing room.
Which leaves the Scotland star in the perfect position to assess how great an achievement winning a treble of titles is, and also what the club must do to improve.
Mulgrew, who was Neil Lennon's first signing when he arrived from Aberdeen in 2010, said the club hoped to keep hold of their best players. "If we want to progress as a club, then that's pretty important," he said.
Mulgrew is sorry to see Samaras become the latest big-name player to exit Parkhead, and paid his own tribute to the winger now heading for the World Cup finals before finding a new club.
"Sami has been a good player for us, especially in Europe, in that lone striker role," said Mulgrew.
"He will be missed in that sense. But I'm sure he'll go on and do well wherever he goes."
Sami picked up four championship medals in his six years at the club, and Mulgrew hopes to emulate his tally next season.
He said: "For me to be sitting here having won three titles is brilliant.
"But it only makes me hungry to do better, not just in the league, but in other competitions.
"It's always good to win the title and lift the trophy. It's harder than a lot of people think.
"You're under a lot of pressure and there are a lot of expectations.
"That's why it's important we pushed on and kept going in the manner we did.
"The more you win titles, the more you want to do it again and again."