'Total machine': The Celtic player who is like nothing Kieran Tierney has seen before

Yet one of his new teammates at Celtic has caught his eye. You could probably guess who, the Duracell Bunny of Scottish football that is Daizen Maeda, last season’s player of the year and the Glasgow side’s current talisman.

“You think, ‘how can he run like that all the time’? said Tierney. “But he's actually like that in training as well and, being away for six years, I've not seen anyone that can sprint like that, consistently sprint and press.”

High praise indeed for the Japanese, who scored 33 goals and provided 12 assists in 51 matches last season. He will be ably supported by Tierney in the upcoming campaign after the fellow 28-year-old signed a five-year deal to return back to Celtic following spells at Arsenal and Real Sociedad.

Tierney may have arrived on a free transfer but he is undoubtedly the marquee signing of the summer for Celtic. A shoo-in as first-choice left-back, he prospect of him and Maeda linking up down that flank has plenty of supporters salivating. They combined to good effect in a 2-0 win over Sporting CP on Wednesday and may get the chance to link up again in Saturday’s home friendly against Newcastle United.

“As a full-back, it’s the amount of times that he helps you defensively as well,” continued Tierney, who watched on from afar while away given he is a huge Celtic fan. “So far I've only been a couple of games, but he’s a joy to play with, so I'd say he's the one [that has stood out the most]. Not that he's surprised me because I watched him for six years, but the fact that he's so consistent in his sprints is incredible.

‘It’s not a brand new system to me’

“You want any winger that you play with, or a centre-back or a centre-mid, the people around you on the pitch, you want to build a connection on and off the park with them, so we'll get there.

“I've watched him play. Even though he might never have seen me, but I know how he plays. I know how him and Greg [Taylor, previous left-back] worked, so I can take from that and learn well. If I'm in this position, I've seen Greg and stuff do this kind of move. So it's not a brand new system to me.

“Some aspects are new and the role that I'm asked to play, but watching them for the last few years under the gaffer, I kind of know what he expects from his left-back as well."

Even in the searing heat of the Algarve, where Celtic faced Sporting during the week, Maeda refused to rest. A clip of him doing press-ups after playing an hour in 30C temperatures went viral. Tierney was more than impressed. "Me and Jamesy [Forrest] were sitting on the bench having a recovery shake after, thinking how hot was that?” smiled Tierney. “And he's doing there doing press-ups. He's a machine. A total machine."

The plan is for Celtic to remain a machine when it comes to Scottish football too. They have dominated the landscape in the period Tierney has been away and his signing is a statement of intent. The Scotland internationalist won three pieces of silverware during his six years at Arsenal and Real Sociedad - an FA Cup and two Community Shields. Celtic have made winning three trophies in one season quite the habit.

Was he ever jealous of Celtic’s medal haul as he watched on from afar? "I wouldn't say envy because as a Celtic fan, so I was absolutely delighted that they're winning trophies,” he replied. “But in the way that you mean, you would, you would love to be a part of Celtic, a successful Celtic team like I was before. But now I'm back here and that's the ambition, is to try and be successful again."

Tierney wanted to come home in his peak

It is important for Tierney that he has returned to his boyhood club while at his peak. Many players choose to come back in their 30s, when perhaps their best days are beyond them. “I think that was another factor why I thought it was kind of, this will be now or never, kind of time,” admitted Tierney. “If I don't come back now and I end up signing somewhere else, I wouldn't want to come back at 33 or that and maybe I'm slowing down. I feel good just now. I'm in a good place and I'm obviously still young just now.”

Tierney’s time at Arsenal was punctuated by some injuries and he was not always a first pick for head coach Mikel Arteta. Yet his experiences at the Emirates, or indeed while on loan in San Sebastian, have made him a better player. Tierney is in no doubt he returns a superior version of himself.

"Even just by age, as the seasons go on, you get experience,” explained Tierney. “But for me, having to move country ... I was only down in England to start with, but then going to Spain and just the different challenges and situations that you come across, the different games that you've played in and been involved in. It's all experience.

“You don't know it at the time, but looking back at the experience that you've had, it's brilliant for a player and it makes you grow."

Even still, there will be nerves and goosebumps when he steps on to the Celtic Park pitch against Newcastle. "It'll be very special,” he added. “It'll be the first time I've been on the park for six years, so it's a long time. That will be amazing."

The Celtic faithful will no doubt feel the same.