Cornwall couldn't bowl on Friday morning because the ICC's playing conditions for Test cricket require players to spend as much time back on the field (capped at 120 minutes) as they spent off it before they are allowed to bowl again. One exception to this rule is if a player suffers an "external injury" resulting from a blow suffered on the field. In this case the player can bowl as soon as they return to the field.

The umpires can also waive the requirement of penalty time if they feel the player was off the field "for other wholly acceptable reasons, which shall not include illness or internal injury."

Illness was Cornwall's reason of absence, which meant he had to serve out his 120-minute penalty time before he was able to resume bowling.

Cornwall's absence had a significant impact on West Indies' fortunes in Dominica. At the time he went out of their attack on day two, he had bowled 11 of India's first 46 overs, during which time they had scored 128 for no loss in response to West Indies' 150 all out.

For one, they were forced to use part-time bowlers for a total of 31 overs. India only scored 94 runs in those part-timer overs, thanks to the slowness of the surface, but they only lost one wicket. Cornwall resumed bowling soon after lunch on day three, and made an almost immediate impact, getting the first ball of his second over to kick at Virat Kohli to have him caught at leg gully. By this time, though, India's lead had already passed 250.

All of West Indies' bowlers were wicketless at that point, but Cornwall had looked their biggest threat, troubling both openers with sharp turn and steep bounce. Over those first 46 overs, Rohit Sharma and Yashasvi Jaiswal had managed a control percentage of 78.5 against Cornwall - they had gone at 83.3% against both Kemar Roach and Alzarri Joseph, and at over 90% against Jason Holder and Jomel Warrican.

India eventually built a first-innings lead of 271 before declaring on the third afternoon. West Indies were always at a disadvantage after being bowled out so cheaply on day one; Cornwall's prolonged absence from the bowling crease probably took away most of their hopes of fighting back.

If the playing conditions hadn't forced Cornwall to wait those two extra hours before he could bowl again, he could have been operating at the start of day three, when India's lead was 162. Cornwall's illness had already put West Indies at a disadvantage; it was an extra dose of punishment that they couldn't use him even when he was available to bowl.

At a wider level, the Cornwall situation highlights the peculiar distinction that the playing conditions make between external injury, internal injury and illness. Thanks to this distinction, a player who has suffered a bruised finger in his non-bowling hand while effecting a stop on the field would be exempt from serving penalty time while a player who has strained a hamstring would not, even if both spent the same amount of time off the field.

This distinction possibly stems from the fact that umpires are immediate eyewitnesses to injuries arising from blows suffered on the field, while they may not be able to confirm or refute claims that a player has a muscular injury or a stomach bug. By not exempting internal injuries and illnesses from penalty time, the playing conditions deny teams a loophole to exploit if they want to rest a bowler on a tiring day.

It's possible to do away with this distinction, though, by having an independent medical authority present at the ground to assist the match officials. It would ensure that teams do not suffer doubly for losing bowlers to unexpected injuries or illnesses. It would ensure that teams are able to use their best bowlers when they are fit and available, which would help safeguard the competitive balance of Test matches as well as their lustre as a spectacle.