The 41-year old German striker, who also spent time with Fulham, Hibernian and Brighton & Hove Albion during his career, was impressed by McFadden a decade ago and is delighted to see him back at Fir Park after finding himself in limbo after spells with Everton, Birmingham City and Sunderland.
"My two years at Motherwell was a wonderful time in my life," Lehmann told SunSport.
"The club went into administration but I worked out a deal to stay and lots of young players came through.
"James was one of those. He was part of a really young team - apart from me!
"He had a little ponytail, then the red streak in his hair later on. I had my earrings - which I wore then and which I wear now. So we got on great!
"James scored in both games and when we played Celtic he destroyed them.
"I remember Celtic in particular. They had really strong players like John Hartson, Chris Sutton and Henrik Larsson but our kids still beat them.
"We counter-attacked brilliantly and it was a great victory. We were a good partnership.
"I watched as James made the breakthrough into the Scotland team and was pleased when he eventually signed for Sunderland in the Premier league.
"It hasn't worked in England so maybe it will be good for him to return home and get his goalscoring ability and confidence back.
"It was the club where he was happiest so maybe he can recapture some of that."