The midfielder has since gone on to become one of the most promising young players in the league.
It was August 2013 when, the then 18-year old, Mowatt made his senior Leeds United bow in a Capital One Cup victory over Doncaster at the Keepmoat Stadium, and the 20-year old has shared his experience of that night.
“I can remember everything about my debut. I had to drive to Thorp Arch to go back to Donny," said Mowatt, in quotes published on the club's official site.
“I can remember at half-time – I’d played well until that point – and I was thinking ‘Get me off, that’ll do me for my debut’, because I didn’t want to do anything wrong.”
“It was a good game for me. I crossed one in and Matt Smith headed it back and Scott Wootton headed it in – I remember it clearly. “
The Whites return there tonight for another league cup clash and Mowatt sees the game as an indicator for how much he has progressed in the intervening years.
“I made my debut there two years ago – in the same cup as well – so it’s like going back two years to see how far I’ve come,” he added.
Very far indeed is the short answer, and last season saw the talented midfielder named Leeds’ player of the year after a terrific campaign.
He is one of several Thorp Arch graduates currently impressing at Elland Road and is part of a production line that is gradually becoming recognised as one of the best in the country.
Tonight's cup tie with Doncaster will indeed be a measure of Mowatt's progress and expect to see more of the creativity and drive that has characterised his Leeds career thus far, should Uwe Rosler give him the nod.