Mikey's been a bit vague since dropping that nugget, but I think there will be a fair bit of strategy involved when it comes to injuries I think... I'm guessing (speculation) that you'll be given the option to continue "playing" the injured person in the match, but their health may/may not deteriorate faster. Ie; hiding them down at fine leg as would happen in 'real cricket' would be the strategic option if they were a bowler and hoping they recovered enough during the test/odi to keep playing a part. Assuming it's in the 'Be A Pro' mode your Captain may want you to continue playing regardless, so you may not have much control in that scenario...
Which would actually be pretty cool.