Mitch Marner who viewed the chance to win the Stanley Cup as coming to the Golden Knights was defeated today. (Images via Getty Images)When Mitch Marner left the franchise, the Toronto Maple Leafs struggled to find the same success as they did before, and former head coach Craig Berube believes the forward’s leadership qualities were a big factor in the team’s decline. Berube sees Marner’s energy and accountability, and emotional support that stats didn’t fully capture.Marner leaves his hometown team, the Toronto Maple Leafs, after nine seasons to join the Vegas Golden Knights. Toronto’s NHL season was a disappointment, but Marner was good in Vegas and showed why his absence was a massive problem for the Maple Leafs.Mitch Marner absence impacts Toronto Maple Leafs after NHL strugglesMitch Marner’s absence created a leadership void that affected the team’s overall identity, said Toronto Maple Leafs coach Craig Berube. The former coach said Marner was an emotional leader who helped set a tone in games and practices.Craig Berube highlights Mitch Marner’s leadership qualitiesCraig Berube, in an interview on the Simmer’s Morning Skate podcast, said Mitch Marner’s communication skills and ability to motivate teammates were impressive. The former Toronto Maple Leafs coach said Marner brought energy, emotion and accountability to games and practices alike.Marner was productive on the ice, but also helped keep the team’s confidence together, Berube said. His vocal presence on the bench and ability to challenge teammates added a leadership element that Toronto struggled to replace.Toronto Maple Leafs face major changes after collapseThe Toronto Maple Leafs had a difficult NHL season after falling from Atlantic Division contenders to one of the league’s bottom teams. The disappointing campaign resulted in major shakeups, including Craig Berube’s departure as head coach and changes in the front office.The franchise was in a new phase, looking for answers to improve team consistency and performance. It wasn't just about replacing Marner with a scorer, but also with a player who can change the culture of the team.Mitch Marner succeeds with Vegas Golden KnightsMitch Marner’s move to the Vegas Golden Knights has produced impressive numbers after he left Toronto. The forward tallied 80 points in 81 regular-season games and was a big factor in Vegas’ playoff run.His success also altered the narrative about his time with the Maple Leafs. Marner may have caught some heat for the lack of playoff success in Toronto, but he was one of the team’s best players in each of his nine seasons.Berube’s remarks underscored the challenge of replacing leadership traits that never appear on a statistics sheet. With the Toronto Maple Leafs moving forward under new ownership, the search for a player who can deliver that same emotional punch is still a priority.Latest NHL news update on Mitch Marner and the Toronto Maple Leafs reminds us of the power of leadership, chemistry and team identity to success. Scoring ability is still important, but the franchise has to re-establish the intangibles that helped define past seasons.