The former England international reports little feedback from Sir Alex Ferguson at the time, recognising that he wasn't a player who needed constant reassurance, and while Carrick clearly settled in quickly, he never rested on his laurels.
He noted: "The beauty of the club is, as much as I settled in and had some level of success, which was fantastic, you never felt settled. It was never enough, no matter what, whether it was winning the league, the Champions League, it was always 'what's next?'
"I never felt ultra-comfortable in terms of 'this is it', you know? It was always pushing for that next thing, and you never really knew how long it was going to last, so you had to just keep pushing. That's the culture that we had at the time, which led to success."
Carrick would go on to lift the Premier League with the Reds in his first season, and a subsequent four more times before his retirement in 2018, not forgetting the UEFA Champions League, FA Cup, four League Cups and countless other pieces of silverware collected in a 12-year playing career at Old Trafford. Success, indeed.
Watch Carrick pull on his boots again in the upcoming Legends match between Celtic and United in Glasgow.