You can, because 3 bowlers carrying an attack makes other even more injury prone. Not only that, but the potency is lost as well.

Lords 2011- Zaheer out, Harbhajan, Ishant & Praveen Kumar had to bowl in both innings the majority of the overs. https://twitter.com/therealcrrao/status/1348870731329720325

Bhajji got ruled out after the 2nd Test. Ishant got ruled out for the last one which meant that an unfit RP was bowling at the oval. Similarly Ishant got injured again in Lords 2014 after his 7 fer & a part of that was him bowling a lot of overs because Binny wasn't good enough

to be a 5th bowler that day. In fact, I'd even say this that a lot of tests IND couldn't even overseas was because they didn't have a 5th bowler. Wellington 2014, Joburg 2013, Cape Town 2011 are the most recent examples that come to mind. A 5th bowler isn't just necessary to keep

your other bowlers fresh, it's necessary for ensure there's no release in pressure either. One of the reasons why Australia couldn't win the BG Trophy in India (2017) was the 5th bowler. Look at the scorecard of Ranchi Test & the overs bowled by O'Keefe.

A 5th bowler would have probably ensured that the 200 odd p'ship between Pujara & Saha never happened. This is why a Ben Stokes, Ravindra Jadeja, Kyle Jameison, Moeen Ali are so valuable in any test side. They just don't help in managing in the work load, but they ensure no let

off for the batting team. And this is why I consider Jack Kallis as one of the all time greats. Without Kallis' bowling or batting, SA would have never managed to have a run of being unbeaten overseas for 9 years in Tests. End of.