Michael Carrick has wasted no time stamping his authority on Manchester United, implementing six key behind-the-scenes changes that have already highlighted the shortcomings of his predecessor, Ruben Amorim. From matchday routines to academy integration, the interim boss has impressed both players and staff in his first week, culminating in a morale-boosting derby victory over Manchester City and a clear shift in culture at Carrington.One of the most immediate and symbolic changes Carrick has made involves his visibility and support for the club's famed youth system, according to Manchester Evening News. In a move that starkly contrasts with the previous regime, Carrick and his backroom staff braved rush hour traffic to attend the Under-21s fixture at Leigh Sports Village on Tuesday. His attendance has been regarded as a gesture to show the youth stars that a path to the first team exists while he is in charge.Amorim’s approach to the academy was notably distant during his 14-month tenure. Despite opportunities to watch games at Old Trafford or the nearby Moss Lane in Altrincham, the Portuguese coach rarely attended. While Erik ten Hag had previously made the effort to visit local youth fixtures, Amorim’s interaction was limited to a casual stroll across the pitches at Carrington. Carrick’s presence at Leigh after just seven days in charge has already won him credit where Amorim failed to engage, fixing what insiders viewed as an "easy win" that was previously ignored.At Carrington, the atmosphere has shifted significantly. Carrick has introduced a new training schedule characterised by shorter but more intense sessions, with a renewed focus on individual improvement plans for specific players. The feedback from the squad has been overwhelmingly positive, with defender Harry Maguire admitting he has been "really impressed" by the detail and energy brought by the new coaching team.Carrick has also adopted a more hands-on approach than Amorim. While the former boss often preferred to observe from a distance, Carrick is actively involved in drills alongside his assistants, Steve Holland and Jonathan Woodgate. The appointment of Holland, a boyhood United fan with vast experience at Chelsea and England, has been hailed as a masterstroke. The dynamic between the staff is reportedly strong, blending different skillsets to create a cohesive coaching unit that is already earning the respect of the players.Looking for smarter football bets? Get expert previews, data-driven predictions & winning insights with GOAL Tips on Telegram. Join our growing community now!The changes have extended to matchday logistics and dressing room culture. Carrick has tweaked the pre-match routine, deciding that the squad should arrive at Old Trafford slightly later than they did under Amorim. While the core principle of travelling together from Carrington remains, the subtle adjustment is designed to usher in a "fresh feeling" and break the monotony of the previous regime.Crucially, Carrick has reinstated the traditional manager’s post-match address. Amorim was known for backing off immediately after the final whistle, preferring to gather his thoughts and speak to players the following day, leaving the squad to hold their own debriefs. Carrick, however, spoke directly to the team in the dressing room following the victory over Manchester City, urging them not to get carried away. He has also shifted the tone of his general addresses, constantly reiterating the "privilege" of working for the club and the importance of enjoyment - a message that seems to be resonating.Add GOAL.com as a preferred source on Google to see more of our reportingPerhaps the most impactful on-pitch change has been the reintegration of Kobbie Mainoo. The young midfielder had been frozen out under Amorim, who doubted his suitability for a 3-4-3 system, leading Mainoo to request a loan move in the summer. Frustrations had boiled over, with family members protesting and the player engaging with critical social media posts.Carrick has immediately restored faith in the 20-year-old, handing him his first Premier League start of the season in the derby. Mainoo repaid that trust with a tireless performance, covering 7.9km and impressing with his defensive work rate. A post-match photo of Carrick offering words of encouragement to Mainoo in the tunnel signalled a new chapter for the midfielder, who looks set to play a key role in United’s push for Champions League qualification.