The skipper bounced into Leeds Beckett's Carnegie School of Sport on Monday morning showing no signs of the stress that gripped his club for most of the 2021/22 Premier League campaign.
He welcomed new faces in Brenden Aaronson, Rasmus Kristensen and latest arrival Darko Gyabi, whose move from Manchester City was shortly to be announced, and caught up with old ones, congratulating Daniel James on his recent engagement.
It has been a big summer, one of change.
Cooper left Scotland's Nations League camp early to travel to Ibiza and marry his long-term partner Abbie Kirk with team-mates past and present in attendance. Kalvin Phillips was among the guests amid growing certainty of a move to Manchester City, which was finally announced on Monday not long after Cooper reported back for pre-season testing. The £45m deal and Phillips' six-year contract were inevitably the talk of the town and Cooper was quick to share his pride on social media.
"Like a proud Father," he Tweeted.
"You have earned this chance and I have no doubt you will deliver like you always did for us. An unbelievable player but I’m more proud of the man you have become! Never change mate. Look after him."
What Phillips and Cooper have gone through at Leeds has bonded them forever. Leading the club they supported as boys back to the Premier League and storming to a top-10 finish as part of Marcelo Bielsa's Elland Road revolution afforded them status in the city that not many can boast.
Keeping the club there last season, though, was an almighty struggle. Cooper and Phillips both tore their hamstrings in the same mid-December game and sat out for months after operations. They returned in time to rejoin the relegation scrap in its death throes and stayed up, just, on the final day.
"I don't even think it was [difficult through injuries] just towards the end of the season, I think that was just the story of our season last year," said Cooper.
"Myself, obviously we lost Kalv, we lost Pat it's difficult replacing that when you have a small squad. And it wasn't just the one or two or three week injuries. There was long, long injuries and and it hit everybody physically but definitely mentally.
"Going into those last few games there was so much pressure on and we know ourselves when you play for Leeds United everything is magnified. So you need to sort of put out the noise outside of the training ground. And Jesse was very good at that. It was always about the group and what we can make an impact on and we stuck to that and we got it over the line in the end and were just delighted and relieved at the end of the season."
Marsch, parachuted into a dog fight to try and lead an injury-ravaged squad, leaned on his captain and six other senior players, Phillips included.
What they achieved together, even if was just three points more than relegated Burnley, was vital for the club's present and future.
Cooper credits the manager and the squad for doing what was necessary, when it mattered.
"On his first day I said you're coming into an unbelievable group who are willing to learn and we're sponges, we can take a lot of information on and adapt to various situations," he said.
"So I'd say as a group, we're probably a manager's dream. I've got nothing but respect for Jesse and his staff and also the lads as well for taking on everything that's been asked.
"The club is going to rebuild, I think. Jesse's got his own ideas. I think he'll be the first to tell you that we didn't quite produce what he wanted to at the end of last season, but I think that was as a result of the situation he was in, it was difficult. It would be difficult for any manager to come in and change the way we played just like that. But the boys did well, I think we showed what we're about.
"We turned up on the day and got the points required and sealed our position in the league for another year and we don't ever want to be in that situation again."
Cooper was no fan of the 'second season syndrome' talk that first emerged around this time last year because he's no believer in that theory. He's a big believer in fresh starts, his team-mates and the power of accountability, though.
The Thorp Arch and Elland Road dressing rooms have lost a big character in Phillips and will lose another in Raphinha but he sees sufficient character still in place.
"[When I signed] we were a club that accepted mediocre," he said.
"I think since Andrea [Radrizzani, owner] and Marcelo came in that's changed a lot, that is helped a lot with success and we were very successful under Marcelo - it's a lot easier to get the dressing room going, then.
"We learned a lot about ourselves last season and coming through that. We learned a lot about each other and we know we can turn up when it matters and when the pressure's on.
"I think we're an honest group. We know if anyone needs a kick up the backside, we don't take it personally. We all want the same thing - to be successful, to win football games. And so we discipline ourselves. We've got an unbelievable group and a group of very good men. We're all willing to do whatever we can to get the points for each other."
Cooper wants that character to be reattached to the belief that coursed through the club en route to ninth-place in the 2020/21 Premier League table. He's aiming for the same thing this season, the 15th of a career that is testament to not giving up when things don't go well.
At first he didn't succeed in the Premier League and had to fight his way back from League Two. At first, at Leeds, he didn't convince and had to fight his way into fans' affections. Last season was not his or Leeds' first brush with adversity but, again, they came through it and lived to fight another day. That day is just starting.
"I struggled to win people over at the start, but I always had confidence in my ability, in my character and what I could do and where I could go. I count my blessings every day but I like to think I've proved a few people wrong over the years and now I just want to improve and get better and I still think I'm doing that.
"And I'm just delighted to be captain of our amazing club and you looked back all those years ago and sometimes you just have a little wow at how far you've come and how proud you can be of yourself, but the work doesn't stop. We're coming into another tough season in the best league in the world, one I'm looking forward to.
"Jesse is brilliant at what he does and he's a great coach and I'm sure he'll drill his ideas into us and when we start the season, we'll know exactly what we're doing.
"We're bringing in top quality players and Champions League, international players, playing at the highest level. So it's only going to benefit us as a team. We've got to integrate and quickly get the boys going fast, show them the Yorkshire culture. They're playing for amazing club, coming into an amazing group of people and hopefully we can have a lot of success with each other.
"It was a stressful [last] season but that's gone now. We've got to be optimistic. We've got to aim as high as we can."