For the 1-1 draw on Saturday, he admitted it was a case of split loyalties for him and his Arsenal-mad family.
Watt, 19, said: "I hope to score in the replay. It's a dream to play Arsenal twice. Hopefully, I can do even better next time at Elland Road.
"It was a strange feeling. I was a bit under pressure obviously because, basically, it was all eyes on me from Arsenal.
"I didn't want to let myself down, the club down and Leeds down, so I had to do the biz.
"Even Arsenal fans were saying, 'I hope you do well but you lose the game'."