Diju started his International career by representing India for Asian junior badminton championship held at Hong Kong in 1997.

In 2002, he and Sanave Thomas won the men's doubles title at the Indian National Championships by defeating Jaseel P. Ismail and Jaison Xavier in four games.

[4] In August 2009, the Diju-Gutta mixed doubles pair became the first Indians to enter the quarterfinals of World Championship.

In the third round they defeated 12th seed polish pair of Robert Mateusiak and Nadieżda Kostiuczyk 21–11, 22–20 in a 31-minute clash.

[6] On 30 August 2009, Diju partnering Jwala Gutta became the first Indian badminton mixed doubles pair to win a Grand Prix Gold title.

They defeated Indonesia's Hendra Aprida Gunawan and Vita Marissa 24–22, 21–18 in the Chinese Taipei Open final.

[8] In December 2009, Diju and his doubles partner Gutta reached the World Superseries Masters final in Johor Bahru, Malaysia.

[9] In the final the Indian pair went down to World Championship bronze medalists Joachim Fischer Nielsen and Christinna Pedersen 14–21, 18–21.

Diju and Gutta pair reached the quarter-finals of the World Championships for the second consecutive year beaten by Koreans Ko Sung-hyun and Ha Jung-eun 21–16, 21–19 having beaten the English pair of Chris Adcock and Gabrielle White and Malaysians Goh Liu Ying and Chan Peng Soon in straight games and overcoming Chayut Triyachart and Yao Lei from Singapore in the pre-quarters in three games.

Diju started his Olympic campaign pairing Jwala Gutta in mixed doubles.