Kuldeep Yadav replacing Yuzvendra Chahal:

In recent times, the leg-spinner Yuzvendra Chahal has struggled to perform well consistently. He is struggling to pick up wickets in regular matches. Due to his recent form, his place in India’s playing XI is insecure.

The other wrist-spinner Kuldeep Yadav can replace Chahal in the next game.
The 25-year-old left-arm chinaman hugely struggled in the last calendar year (2019), and lost his place from the playing XI.
Now, he is trying hard to return to his old form. Though he hasn’t found his old consistency yet, he has shown improvement with the ball in most recent limited-overs matches.