Thirlwell made 66 appearances for the Black Cats, plus 26 as a used substitute, and also had a two-month loan spell at Swindon Town as a 20-year old in late 1999, before joining Sheffield United in the summer of 2004 after spending seven years on Wearside.
He then moved down to the East Midlands for the start of 2005-06 season, initially joining Derby County from the Blades, who he made 28 starts for, initally on loan in a move which was later made permanent, so he could play in the Rams' opening game of the campaign, a 1-1 draw at home to Brighton. Paul has made 17 starts, plus six as a used substitute for the Pride Park club, the last of those games in the first eleven coming in a 2-2 local derby draw at Leicester City back on February the 14th 2006.