The academy product was handed a start at Old Trafford this evening as Ole Gunnar Solskjaer made ten changes in preparation for the big match against Liverpool in 48 hours.
And while partnering Eric Bailly at the heart of United's backline, the 23-year-old had his watch on his wrist - clearly trying to get those extra steps in for the day.
Fans had never seen anything like this before in the Premier League and so there was a wave of reaction on social media:
Tuanzebe's watch wasn't actually an apple one, it was a whoop fitness tracker watch that is used by NFL players and professional golfers.
If Tuanzebe had alerts from the Premier League app on his watch, then it would have told him that his side's 2-1 defeat at home to Leicester means rivals Manchester City have now won the title for the fifth time.
City, who are set to receive a guard of honour against Newcastle on Friday, have now finished above United for eight straight seasons.
- Manchester United fans think they've found the perfect solution for Casemiro's suspension
- Newcastle United fans certain club are signing James Maddison after seeing his social media
- Arsenal fans in Uganda arrested for celebrating Man United win questioned as they 'didn't know when Invincibles was'
- Manchester United fans point out substitution is to blame for conceding late goals