This is the day many Arsenal fans have been looking forward to for years. Too many years, sadly. And if they are hoping for signs that the Arsene Wenger era is over, I think we have seen them under Unai Emery already.
When did you ever see Arsenal being filmed in pre-season working on their strength and fitness in training? It's certainly not the way Wenger approached things. I'm not saying he didn't want discipline and togetherness in his team, he just never worked on it. Arsenal will be more regimented and united under Emery.
He will have made an impression on his first day in the job. That first meeting with the players is so important. It is the coach's opportunity to get his new players to buy into his mentality. Even when I knew what the manager was going to say, I would be looking forward to that first day of pre-season. But every player loves an edge. I bet every Arsenal player was desperate to be there for Emery's first day.
The days of just walking in and having a little team-talk are gone. Players need information as well as stimulation. The manager needs to be prepared for that first meeting and Emery strikes me as that type of coach, so he will not have overlooked the importance of first impressions, particularly on those who have played under Wenger for so long.
During the summer, he will have had little conversations with the players on an individual and group basis and over the season, as he gets to know their different personalities better, they will have more one-on-ones. These are important for players under a new manager. It's their chance to figure out what he thinks of them. They might be only little chats, but they are important.
Arsenal seem to have their prep work done and no doubt they are ready to go. They did their business in the early close-season, signing five new players and releasing Jack Wilshere. Until last week's ownership announcement, it had been a settled summer at the Emirates.
Today, against the champions, I look forward to seeing them on the front foot, closing down the opposition and being a bit more aggressive than we have been used to seeing them. With a few Manchester City players back late from the World Cup, I expect Arsenal to dominate at an expectant Emirates and with the quality of their offensive players, they can hurt Pep Guardiola's men.
It was the philosophy of the previous manager that made Arsenal so loose for so long. If Wenger wanted his team to be tighter, he could have done that but he was never going to change. So Emery will have made an immediate impact on that front. Whether it lasts, only time will tell. I think Guardiola will be happy with a point today, and he'll probably get it.
For years Jose Mourinho has been the expert at instilling rigid systems into his team, through man-management, structure, discipline and options. But he might as well have a piece of string on all 11 players because he wants that much control from the sidelines all the time.
Mourinho is stricter on his players. How can he give Marcus Rashford the number 10 shirt? You would like to think he is giving him that number and really saying, 'go out and do your stuff'. But it won't be that way. It's just a gesture.
Emery is much looser and he won't be so controlling but he might be just what the Arsenal players need. He clearly built a very good, well-disciplined side at Sevilla and if he has quickly instilled that same discipline in this team, with the quality they have going forward, Arsenal could make a very good start to this season. Looking at their fixtures, they have the potential to be top and gaining momentum by the end of October.
As for Manchester City, how can they keep the ball rolling? They will want momentum and to get back into shape quickly and create more memories. Because of the levels they reached last year, and what they brought to the table, they might make a slow start but as the season goes by, they will be up there. They will win the league.
Guardiola will insist his players have the World Cup out of their systems, get back to the club mentality, Monday to Sunday, what they do best. You know he will not accept anyone who is not on the page but I still think it will take them time before they start steam-rolling teams again. And they will.
Their only major signing was Riyad Mahrez at £60m. I can't see him being a regular starter because I am not 100 per cent sure he is up to the level of those who won the title last season, especially without the ball. That is massive for the Man City players, and any player in a Guardiola team for that matter.
Mahrez had his moments at Leicester and I can see him playing out wide when he is in the side, but I would not select him as a number 10 ahead of Raheem Sterling. He is a player who will start because he creates so much space for other players and I would imagine he will be signing a new contract at Manchester City very soon.