Prannoy, searching for his first BWF title in five years, beat Tsuneyama 25-23, 22-20 in the 60-minute men's singles quarterfinal clash to reach the last-four stage.
The four injured are in stable condition now and are being closely monitored.
Although Sindhu did manage to save as many as six match points, as it turned out, she was only delaying the inevitable.
Sindhu raced into the second round of the competition after winning a first-round match which lasted 35 minutes.
World number six Sindhu had a dream run at the World Championships in Basel, Switzerland, winning the title last year, but she made early exits in the rest of the season.
Thailand's Ratchanok Intanon beat Spanish badminton star Carolina Marin 21-9, 22-20 here on Sunday, clinching the Malaysia Masters final in just 42 minutes.
Saina will now take on second seed Japan's Nozomi Okuhara.
But the resilient Thai saved all of them, taking the score to 20-20 when the Spaniard netted a smash.
Kashyap will next face sixth seed Anthony Sinisuka Ginting of Indonesia.
Saina has been struggling ever since, limping out of the Olympics last year with a knee injury.
