The former Rangers and Scotland goalkeeper spent a short amount of time with United in 2001 and has explained how retiring midfield ace Beckham would ask him to come back out so he could hit free-kicks at him in goal.
"I was David Beckham's lackey," he wrote in his column for SunSport.
"A 36-year-old guinea pig he used to ping balls at for fun.
"When all I wanted to do was go home and put my feet up, Becks would drag me back out on to Manchester United's Carrington training pitch for extra shooting practice.
"That is my abiding memory of the man who announced his retirement from football yesterday.
"A kid eager to learn, to better himself and always willing to listen to advice.
"I was a boyhood United fan and loved the three months I had at Old Trafford with Becks and Co.
"Although I was close to slapping Becks by the end, it was an experience - even for someone at my age.
"Every day, and I mean every day, Beckham would ask me to stay behind for free-kick practice.
"I agreed at first, but by the end I was sick of the sight of him.
"He would wheel this wee trolley out on to the pitch. On the trolley would be four or five dummies who would form the wall.
"Becks would then spend anything from 45 minutes to an hour blasting shots at me.
"It is hard to judge him overall because I was only at United for three months.
"But it is fair to say Becks is one of the most dedicated and professional people I ever worked with."