The Japanese midfielder made his national debut earlier this year while club commitments at home and abroad have seen the 24-year-old rack up 17 appearances inside three months.
Settling into a new country has also taken its toll but despite the fatigue – which he claims even resulted in double-vision during one training session – he is determined to help his team clinch the cinch Premiership title and maintain his role in Ange Postecoglou’s first team since signing in January.
"Since my debut against Hibernian I've felt the intensity of the European game,” he told Sportiva. "But for what feels like the first time, I'm definitely feeling emotional and physical fatigue.
“It's been three months since I arrived in Glasgow and getting used to a new environment on and off the pitch has been trial and error.
"In Japan there were ways I could refresh myself and take a mental break but that's difficult when you're playing so frequently.
"There are times when I can't make a run on goal, or hold back on the attack to preserve the team's balance, and have to recognise my fatigue.
"For the national team I had to go to Australia, then Japan, and back to Scotland. It was my first call-up as an overseas player. On my first day back at Celtic there was a moment I saw two balls and was clearly jet-lagged but in Europe you need to be tough enough to stay fit and fight for your position.”
Hatate has only sat out two Celtic games since signing and has impacted some of the team’s biggest results including two Premiership Old Firm wins – the second after returning from Japan duty against Vietnam.
"To start against Rangers gave me a lot of confidence. It was huge to be able to help create the equaliser. I didn't score a goal or record an assist, but it was huge that I was able to leave my mark on the team's victory.
"I definitely feel tired but I want to keep doing whatever I can to help the team win the league, and I think I'll become tougher and stronger as a result."