Akash Deep was one of the better performers for India so far, and his injury is going to have a negative impact. Bumrah usually plays in alternate test matches, so there is a chance that he will sit out of the fourth match. He performed really well in the third test, taking 5 wickets in the first innings, and then two more in the second. BTW, the latest news from the Indian camp is that Nitish Kumar Reddy is out of the England tour due to a severe knee injury. He maybe replaced by Shardul Thakur in the XI.
Yes, many of the Indian team are injured. These injuries will make their team very worried. But I think that the Indian cricket team has the ability to fill these gaps. If they cannot fill the entire gap, then they will probably fill a lot. But yes, the match will be very difficult for India. Because many of their good players are injured. India has faced more losses due to the high number of bowling injuries.