The relationship between Flyers assistant coach Michel Therrien and new head coach Alain Vigneault goes back many years. However, the upcoming 2019-20 season will be the first time the two have worked together in the National Hockey League.

"We have been good friends for a long time. We like each other, and respect each other. The thing you learn with hockey is that you never know what will happen in the future. I replaced Alain in Montreal [as head coach during the 2001-02 season]. During the offseason, we get together a lot in Florida. We have dinner together and just talk. We both thought it would be great someday if we got to work together in the NHL," Therrien said.

Therrien chuckled when asked about being on the other side of two of the Flyers' rivalries for much of his career -- the longtime archrivalry with the Pittsburgh Penguins and the spikes in animosity with the Montreal Canadiens.

"It's great. Rivalries are good for hockey, and a lot of fun. I enjoyed the rivalry with Philly, as a coach. Our players in Wilkes Barre and Pittsburgh grew up with the rivalry as pros, and that makes for great hockey. You have to respect your rival to want so bad to beat them. I always had a lot of respect for the Flyers," Therrien said.

During his nearly 30-year coaching career at the junior (QMJHL), AHL and NHL levels, Therrien has almost exclusively been a head coach. He said that, for three specific and equally important reasons, he's excited to join the Flyers as an assistant under Vigneault.

One reason is the experience and mix on the Flyers coaching staff. The Flyers coaching staff now is among the most seasoned in the NHL in terms of head coaching experience: a total of 2,454 games in the NHL regular season. Between Vigneault, Therrien and Yeo, there is a combined head coaching record of 1,269 wins, 900 losses, 61 ties (Vigneault and Therrien pre-2004) and 226 regulation ties post 2003-04 season that ended in an overtime or shootout loss.

"Alain is a great person, fun to be around and a smart hockey coach. But it's not just Alain. I think Alain and Chuck [Fletcher] have put together a good staff. Everyone on the staff has something to add to make us better, and that's what you need. I've worked with Mike [Yeo] as my assistant before in Wilkes Barre and Pittsburgh. I know Chuck well from when he was [assistant GM] in Pittsburgh and when he hired me in Minnesota [as a part-time pro scout in between coaching jobs]. Everyone knows Lappy [Ian Laperriere]. We have already had some great discussions about the players on the team that has helped me start to put my ideas together," said Therrien.

"That's what you need with a staff when you are head coach; guys who can add to the team and that you trust because you spend a lot of time together. You have to be comfortable together. Alain always has good staffs, because he sees it like I do. I gave Mike [Yeo] a chance to be my assistant in Wilkes Barre, and I brought him with me to Pittsburgh. I had Gerard Gallant with me in Montreal. I knew these guys were really smart hockey people. Every coach needs that, because you have to work together as a team. We've already spent a little time together as a staff. I really think we will have that chemistry on our staff; I know it when I see it."

Reason number two for Therrien: the depth he sees on the Flyers' roster and the potential for it to steeply cut its goals against average and correspondingly channel it into scoring more goals than the club's 18th rank in 2018-19.

"We have the ability to score goals and we're going to play the right way; 200-feet. That's our job as a coaching staff. Everyone has to know what's expected and be accountable to the expectation," Therrien said.

"In terms of the system, I have ideas on some things we can do. Alain has ideas. Mike has ideas. Lappy has ideas. We'll go over everything next month and we'll have a plan for camp. Then you see what happens in camp, and you adjust when you have to adjust."

Therrien said that he has some preliminary ideas on forward line combinations the team can experiment with at camp but those won't start to crystalize into an early camp plan until the Flyers coaching staff has week-long meetings in August and a follow-up shortly after Labor Day.

However, one key system trait that Therrien says that he already foresees is that the team's centers will be the backbone of the forward corps. The veteran coach noted that the group is now deep enough that Claude Giroux -- who returned to the middle for a portion of last season with Couturier moving to another line due to a need to spread the wealth -- can exclusively play left wing barring emergency need or specific situations. One of the best faceoff men in the NHL, Giroux will continue to take a lot of right circle draws.

"We are deep down the middle, at center and on D, which is important in the game. Chuck was aggressive to address that this summer. You need that depth to win. In terms of the forwards, think we can do a lot to build around what we've got at center. The addition of Kevin Hayes is a big thing for us. It's matchups with the other team, and it's competition on your roster to play in the situations everyone wants to lay. Sean Couturier is one of the best all-around centers in the league. Hayes is good all-around. Now there's more chance for Nolan Patrick to keep developing and grow into the player we think he will be. Scott Laughton gives us a lot of depth, and he's good in his role," Therrien said.

Therrien emphasized that staying on-system on both sides of the puck will be a consistent expectation for everyone on the team, regardless of position. The entire coaching staff, from Vigneault right on through all of his assistants, will harp on this from the first day of camp onward. This will include aspects such as forward accountability for weak side winger reads and positioning, back pressure when not in possession of the puck and for decisions made with the puck between the blue lines and high in the attack zone.

"I believe in creativity. I want our guys to be creative with the puck. It has to be smart. Play the right way, and then you will have the situations where a skill player can be creative. Some teams play one system, some teams play another. Teams that win play the right way in their system, not just some of the time but [in a] consistent way. It's about habit; get into good ones and you become a tough team to play against," Therrien.

One of Therrien's primary responsibilities on the staff will be to coach the power play. This is an area that requires a reboot, as the club almost inexplicably finished at just 17.1 percent (tied for 21st in the NHL least season) after finishing in the 20 percent vicinity (19.5 or above, with a 23.4 percent high-water mark in 2014-15) in five of the previous seasons. The Flyers' 2018-19 power play numbers were their lowest since 2010-11.

"I have my own vision on the power play. We've already talked about it with AV. We need to raise the standard. My responsibility to have the confidence to have success. I'll talk to the players and get their vision, too," Therrien said.

Last season, the Flyers tried to get the stalled power play going via a wide array of tweaks; some subtle, some major with shifts in both personnel and alignment. One major change was to move all lefthanders to the left side and all righthanders to the right, which included relocating Giroux from his longtime "office" on the left half-boards over the right side and Jakub Voracek from his customary spot of moving up and down the right side, from the point down to the bottom of the circle.

"Different teams have different power play systems. You can have success with everyone on their natural side or some guys on their off-side; it depends. That's something we will discuss in more detail as we have our meetings and get ready for camp. In general, I think if players are comfortable and confident, that's how you should go," Therrien said.

"One thing for me with the power play, I believe in being aggressive around the net. Get pucks and bodies to the net. Everywhere I've coached, that's been important in our success. There are different ways to do that with how you set up and move the puck, but you want the pucks in that [high-danger] area."

The Flyers power play issues last season had nothing to do with "too much predictability." Former assistant coach Kris Knoblauch, in conjunction with then-associate head coach Scott Gordon tried many different things to spark the man advantage apart from trying alignment switch-ups.

Generally last season, the Flyers (like the majority of teams in today's NHL) featured four forwards and one defenseman (most commonly Shayne Gostisbehere) on their top power play unit. However, for a little while, the team even experimented with a five-forward power play. On the second unit, the Flyers sometimes went with four forwards and one defenseman (most commonly Ivan Provorov) in an umbrella formation similar to the first unit and sometimes a more old-school arrangement with two defensemen (Provorov and Travis Sanheim) at the points.

What can Flyers fans expect from a Therrien-coached power play?

"I think, as long as you have a defenseman who can do it, it's usually good these days to have one defenseman and four forwards on the units. Most likely, we will have that on both units but we will see. Gostisbehere has been good at that most of his career. You need to have two good units. We have other defensemen who can do it, beyond Gostisbehere. Provorov and Sanheim have potential to do it. Matt Niskanen has played some power play over the years, too. So we have options and competition," Therrien said.

As a head coach, Therrien established a reputation for being a hard-pushing type with players within the hockey realm but a fun-loving sort in his time away from the ice. He said that there are adjustments to make from being a head coach to an assistant but these are primarily in terms of performing specific responsibilities and addressing matters with players. The personalities themselves have to be genuine, regardless of someone's role.

"I believe you have to be yourself to be a success. You have to remember that it's always about the team and winning. That's why I am here. That's why we are all here," Therrien said.