Showed great potential as a youngster and represented England Under 17 against Ireland 1999.
Toured Malaysia with England Under 19 and was selected for the Youth World Cup in Sri Lanka in 1999-2000.
Made his first class debut in 2002 against West Indies A but looked to be on his way out of Edgbaston when he was told at the end of the 2003 season that he was free to find a new county, even though he had a year remaining on his Warwickshire contract.
Decided to stay to fight for his place but his prospects of making Warwickshire reconsider their decision appeared to have disappeared when he missed the first three months of the 2004 season with a stress fracture of the back.
But he was rewarded for a series of impressive performances in the second team on his return with a new one-year contract and selection for the Frizzell County Championship game against Northamptonshire at Wantage Road.
Made an immediate impact, taking 3-1 in 10 balls before finishing with figures of 3-60. Firstly he bowled Gerard Brophy, who offered no stroke, then pinned Irishman Andrew White lbw with his next ball.
Ben Phillips then survived the hat-trick ball but perished in Warren's next over when he pushed forward a thin edge to wicket-keeper Tony Frost.
Struggled to hold down a first eleven place during 2005 and managed to play in only four championshp games.