But, like his team-mates, the Easter Road newcomer has had to adapt and says a fortuitous piece of programming has given him some more insight into the man who will now steer his introduction to the Scottish Premiership.
Since agreeing a pre-contract back in July, the US international winger has closely followed the fortunes and form of the Leith club but that preparation was overtaken by events when Jack Ross was sacked and Shaun Maloney was appointed just as the MLS star crossed the Atlantic for his fresh life in Scotland.
“As soon as I agreed to sign, in fact even before that, when I was in talks I started to watch as many matches as I could, whether they were pre-season games or cup games or whatever, I was fully invested.
“I have watched every single game since I signed.
“So yeah, in that sense it has helped me see what the team is about and see some of the guys.
“Obviously, though, with the managerial switch there are some changes to the tactics and what not from what I watched initially. But, we adapt as players.”
He had envisaged starting the new year and the new chapter of his career with the Edinburgh derby but the rise in omicron cases saw the top tier enter the winter break early.
While there was frustration that his long wait to be involved would be prolonged, the fixture-free spell has given Maloney time to imprint his vision and playing style on the whole squad before they kick off the second half of the season. It has also given them all time to bed in and get to know each other.
“I don’t think my role will change much. I am going to continue to focus on what I can control.”
Knowing very little about his new boss when he was first named, Mueller says the past few weeks have been educational. The two men share a common connection to Chicago, Mueller’s home city and the place Maloney sampled the MLS, as part of the Chicago Fire roster, and there are other similarities, according to the former Orlando City player.
It means he has a manager with an understanding of Mueller’s background and level, which he hopes will prove beneficial. But, a strong advocate of self-belief and motivation, having penned his own book called Bet on Yourself, the 25-year-old knows it will boil down to what he produces on the training pitch and when the competitive action gets underway.
“I didn’t know too much [about his new gaffer], to be honest. We kind of had the Chicago connection because he had been there and I am from Chicago as well.
“I think he only spent a few months there playing with the Chicago Fire but he said the city was lovely. We spoke about the city and the States in general and how far Major League Soccer has come. That was a good chat and a good way to break the ice.
“I guess in the slightest bit that it could help me and I’ll take whatever I can get at this point. But, I’m looking to build on it.
“I’ve heard he was a great player and knowing he was a wide player I think he can be a big help to me.
“I was actually watching Sky Sports yesterday and there was an old Celtic against Rangers game on, from like 2009, and he featured in it.
“So I got to see a bit of film work from his playing days!
“So, yeah, I’m really looking forward to working with him. Even with our playing styles, he was a bit shorter like me and kind of crafty on the ball, good agility and had the ability to create things, take people on one v one.
“So I am really looking forward to seeing what I can pull into my game.”
An ambitious player, while he could have remained in the MLS and chased success and earned decent money, he says he had the drive to expand his horizons..
“I don’t want to speak for everybody coming across from the States but for me my dream was always to play in Europe since I was a little kid.
“You can obviously sign a new contract with a club in the States and make a lot more money and be content and comfortable with being there.
“But obviously the guys who have big dreams and want to challenge themselves, go to a new environment and get out of their comfort zones and see what they can accomplish. Making the move itself speaks more about the players than anything else.”
And, opening himself up to new things applies on and off the field.
So far he and wife Lyss have tackled Edinburgh like tourists, being photographed with an owl, and Mueller believes it was a positive sign.
“The owl has always been a sign for me, which I know sounds weird, but the fact that I saw a real owl for the first time in my life, on the Royal Mile, was not a coincidence, I can guarantee you that!”
Loving the passion of the Scottish fans, he says that Hibs and Hearts supporters have approached him, the former making it clear that a goal and win against the latter is expected and, while the crowd at Celtic Park tonight will not be the largest he has played in front of, he is expecting a different atmosphere.
“I’m really looking forward to it. The rivalry that was in Orlando and Atlanta… there could be about 80,000 people at that game.
“But I don’t know if the hostility and environment necessarily matches Celtic Park. But I came to play in games like this. I’m really thrilled and excited for the opportunity.”