Carroll, 19, made his debut against Hearts in the Europa League earlier this season and has since gone on to make six more first-team appearances.

Derby boss Nigel Clough is a big admirer of the diminutive playmaker, who earned a call up to the England Under-21 squad in November.

Clough told the npower Championship side's website, www.dcfc.co.uk: "He's a highly regarded young player and we've monitored his progress for a considerable amount of time."

Spurs also confirmed this afternoon that 20-year-old midfielder John Bostock has joined League One promotion chasers Sheffield Wednesday on loan until the end of the season.