Olympic bronze-medallist Saina, who was in red-hot form last month as she led India to their maiden bronze medal at the Uber Cup in New Delhi, decided to skip the Japan Open due to fatigue and concentrate on the next two events at Indonesia and Australia later in the month.
In Saina's absence, Sindhu and young Tanvi Lad will represent India in women's singles, while Srikanth will spearhead the challenge in the men's singles.
The World No 10 Indian will now take on Xue Yao in her campaign-opener on Wednesday. She had beaten the Chinese at the Indian Super Series in New Delhi last April but she has to be careful as the world no 10 Xue had tasted success against Sindhu during the 2011 China Open.
Fourth seeded Korean Ji Hyun Sung is likely to wait for Sindhu in the next round if she can cross the opening hurdle.
However, it will be once again a very difficult road as even if he can cross the first hurdle, he will run into the world number one Lee Chong Wei, against whom he had lost in straight games when India had played Malaysia in the campaign opener in Thomas Cup.