So impressed was Higgins by the Galliagh native's attitude and ability, showcased in recent Derry U19 fixtures, that he fast-tracked the youngster into the senior squad for last Monday night's trip to UCD - a proud moment for his family at the Belfield Bowl.
McCallion became the youngest ever Derry player to sign professional terms at the age of 16 last January as he made it onto the first rung of the ladder, that three-year deal proof of how highly he's rated by the Brandywell club's coaching staff.
The versatile former Tristar and Don Bosco's defender turns 17 years-old on Friday and will once again form part of Higgins' first team panel for the first North West derby of the season in Ballybofey the following day.
It's a clear message from the City boss that talent and hard work will be rewarded with a pathway to the first team with Higgins, a regular spectator at the club's U19 fixtures, insisting McCallion's elevation to the senior squad is on merit.
"From the first day I saw him play he caught my eye for different reasons," explained the City manager. "Obviously he's very good but born leaders are dying out of the game and seeing someone so young with exceptional leadership qualities is refreshing and it's strange to see.
"He's in the squad on merit. Having watched him play quite a few times his rate of improvement has been exceptional. He's not in the squad for show, he deserves his place. He's been the outstanding performer in the U19s over recent weeks."
Higgins believes McCallion has hit a level of maturity to experience professional football in a competitive way with the Derry first team squad and while he still has a great margin of evolution to reach the next level, the City supremo reckons the St Brigid's College student has the character to become a success in any walk of life.
"He's the sort of character that, no matter what he does in life, whether it's football or after football, he's the type of character that will be a success. Ability is only a small percentage of what's needed to go further in the game but he has all the characteristics. A lot of things can happen with drive and determination, he definitely could go a long way.
"We want him to keep improving," he added. "He's extremely well educated and his school speaks very highly of him but it's important that he balances the two well (education and football) and doesn't get distracted. I'm confident he's got the personality to handle the two equally as well."
Excused from school to travel with the first team to Dublin on Monday night, McCallion, who was named U17 Players' Player of the Year in 2021, will have benefited from the matchday experience.
His father Declan, who works in Dublin, took the opportunity to travel across the capital to make sure he wouldn't miss a significant milestone in his son's development and proudly documented the moment by taking footage of the pre-match warm-ups.
Higgins reckons that experience will serve the Northern Ireland underage international well.
"His experience travelling with the first team for Monday's match will stand to him, being among top professionals, and he'll be in the squad again on Saturday because he deserves it."
Commenting after Monday night's 2-0 win over UCD, Derry City assistant manager, Alan Reynolds also praised McCallion for his attitude and predicted a bright future should he remain grounded and continue to work hard.
"I have to say Ruaidhri speaks very highly of him," said Reynolds. "He watched him on Sunday for the U19s (2-0 defeat to Drogheda United at Brandywell) and drafted him in on the back of that performance. He has a great attitude and is improving all the time.
"I suppose when school is over and the holidays come, he will be in training with us more and we can try and help him develop but if he keeps his feet on the ground and has a good attitude, then he has a chance."