The 22-year-old attacker has been ruled out of all competitive action until the New Year.
Tottenham made the announcement on their official website on Friday morning, stating that the Englishman has undergone surgery on his right ankle.
The England Under-21 international originally sustained the injury in a challenge against Sweden during the summer's European Under-21 Championships, which ruled him out for the rest of the tournament.
Pritchard, who can feature as a winger or as an attacking midfielder, will not play any competitive football until January 2015.
Pritchard, who has played just twice in the Premier League for Tottenham, is one of the most promising young players on the books of the North London outfit.
The 22-year-old enjoyed a great season for Brentford in 2014-15 and helped the Bees reach the Championship playoffs.
The youngster scored 11 goals and created 111 chances in 46 appearances in the Championship for Brentford last season.
Following the announcement of the injury to Pritchard, former Tottenham attacking midfielder Ricketts and Spurs fans took to Twitter to have their say.
So unfortunate for Pritchard. Signs all pointed to this season being his chance to break through. Hope he recovers soon #coys— Ryan Helms (@Univarn) October 9, 2015