Niraj Patel played Under-16 and Under-19 cricket for Gujarat from 1995 to 1997 before graduating to the state side. He scored 62 on Ranji debut and was included in India's U-19 squad for the World Cup in 1999. Out of the seven matches he featured in, Patel got to bat in only four and averaged 66.5 with the bat. The 2004-05 season was important in reviving his career. Niraj topped the run-charts in the league phases of both the Ranji Trophy and the Ranji ODIs, where he averaged 103 in four games. In 2005 he was also picked in the India A side against the visiting Pakistanis. Then in 2008, Niraj got to play with the likes of Shane Warne and Shane Watson when he was signed on by the Rajasthan Royals in the Indian Premier League. He scored a nerveless 29-ball 40 to clinch a last-ball win against Mumbai in Rajasthan's penultimate league game.
