Osman had only played a couple of games for Everton and a loan spell at Carlisle to his name when he arrived at Pride Park midway through the 2003-04 season.
The Rams were fighting to avoid the drop into League One at the time but put together a strong finish to the season to drag themselves out of trouble.
Osman played in 17 of those games - many alongside Tom in a three-man midfield - and Tom described his form as 'inspirational'.
He took that form back to Merseyside and was one of the finds of the season as Everton claimed a Champions League spot with six goals in 29 Premiership appearances.
Leon was one of the main reasons Derby stayed up two seasons ago, my first season as a regular
He arrived just after Christmas and was an inspiration.
"I played with him in midfield and he was the player who had license to bomb forward and he did that really well, scoring goals and setting them up.
"He's not exceptionally quick but he has great feet and it's impossible to knock him off the ball. His vision and passing ability is second to none.
"It's nice to see him do so well in the Premiership. Derby kick started his career, he did well at Derby and things went from strength to strength when he got back to Everton."
Tom Huddlestone credits Everton's Leon Osman with helping Derby County avoid relegation two seasons ago.