Not since goalkeeper Lionel Perez in 1998 had an individual swapped red-and-white for black-and-white in the north-east, and the repercussions were not lost on the 24-year-old.
Born just a few miles away from St. James’ Park, the lifelong Magpies fan came through the Black Cats’ youth ranks, signing his first contract with the club back in 2008.
The deal prompted a mixed response, with Geordie fans still smarting after Colback scored against the Toon during last season’s derby.
Meanwhile, on Wearside, the thought of losing a crowd favourite to their most hated rivals stuck in the throat of many a Sunderland supporter.
However, since the switch was confirmed in June, the former Ipswich Town loanee has gone quietly about his business, notching six pre-season appearances with minimum fuss.
His assured presence in United’s engine room underlines his efficiency, with hard work and stable possession at the heart of everything Colback brings to the side.
Off the pitch, he displays a similar sense of level-headedness, and he has described his new employers as "a club looking to go places."
In an interview with the Daily Mail’s Craig Hope, the midfielder said:
There might be a bit more pressure—the fact I’ve come from Sunderland—and I’ve got to try to turn the fans’ heads at Newcastle and win them over. But it’s something I’m relishing.
I have come to play for my hometown club, the club my family has supported and I have supported—that was the biggest thing.
Neat and tidy, and with a great amount of self-confidence, Colback will bring an enthusiasm to the Toon’s middle third that was sorely missing for long spells last term.
In an adventurous formation, his direct style sees him find some useful positions, while an abundance of strength makes him a useful ally when backs are pressed firmly against the wall.
His initial battle will be to win over the remaining skeptics who refuse to view his former allegiance with anything less than unease.
However, once the campaign gets underway, it won’t be histrionics that makes the doubters eat their words, but a resolute determination to fulfil a boyhood dream.