The 29-year-old is set to make his return to competitive action in claret and amber against Dundee United on Tuesday night after signing a deal until the end of the season.
McFadden made his name as a teenager at Fir Park, scoring 32 goals before joining Everton in August 2003.
And he has chosen the Lanarkshire club as the ideal place to rejuvenate his career, which stalled when he damaged his cruciate ligament in September 2010, not long after winning his 48th international cap against Liechtenstein.
McFadden left Birmingham before recovering from his knee injury and only made a total of 11 appearances, mostly off the bench, in subsequent spells with Everton and Sunderland.
But a second training stint at Motherwell this season has resulted in him signing for his first club and he is determined to prove the doubters wrong.
McFadden, who has scored 15 goals for Scotland, told MFCTV: "I was out for over a year with my injury and it took me a wee while, even when I was fit and training, to get back to a level I was happy with.
"I never really managed to get a run of games to get back to my best. This is the perfect opportunity for me to do that and hopefully I can do that in the next couple of weeks.
"The last week while people have been questioning my fitness and my ability to play games and get back to the level I was at.
"Hopefully this is the springboard for me to get a good run of games and let people see I'm fine and over my injury and ready to play. Obviously I'd love to play for Scotland again."