It's a select group; those who have only played in one Premier League match and scored. This week we remember the four "one-hit wonders".
"He asked me if I was ready and wanted to play," Harrop recalls. "I didn't know if he was being serious so I just tried to be enthusiastic and said, 'I'm ready, I want my chance.'
"He said, 'Well you’re going to get it, I'm going to play you.' I kept it on the quiet until the day. I only told my mum, dad and sister."
The midfielder, aged 21 at the time, made his debut against Crystal Palace at Old Trafford and scored a fine 15th-minute opener in a 2-0 win.
Jinking into the box from the left side and firing powerfully across Wayne Hennessey, Harrop became the fourth and most recent player to score in their single Premier League appearance.
'It was hard to leave'
Despite the success of his debut, he departed Man Utd a month later, joining Championship club Preston North End.
"It was hard to leave," says Harrop. "They offered me a three-year contract but before that match I'd already thought about taking a step somewhere else, to go and play and prove myself.
"I don't want to stay in the 'one and only' club. I'm still young, I'm only 22, so hopefully I'll make that step and score a few more in the Premier League."