Dennis Schofield, who worked on a part-time basis for City, spotted a young Giggs in 1985 and immediately tried to make him part of the club's youth setup.
However, when the time came to convince Giggs to commit his professional future at the age of 14, United boss Sir Alex Ferguson reacted quicker and was able to convince the Welshman to sign on at Old Trafford.
"This lad on the left wing, right away you could tell he had something, he was brilliant," Schofield told the Premier League's official website. "He had the touches of a professional so I signed him on and we played him at the match at the weekend and believe me he was like a gazelle going up the line."
"Along the line somebody mentioned that he was a United fan, but I thought we would try and get him to sign on. The then manager of Man City said we'd make arrangements to get him signed on.
"Then Sir Alex Ferguson was sat in his house at 14 and signed him and our chief man at Man City was sat in his office waiting for [Giggs] to come to him. It was bad thing."
Giggs, who is still playing for United, has won 34 major honours with the Red Devils.