I honestly don't think that's needed at all. The amount of resources required to have enough various soundbites of players saying things would, again, take up valuable space for better game mechanics and animations. I think a variety of better crowd responses to events is prolly more in the realm of possibilities. Simple animations (much like in C09/IC10) of a batsman getting frustrated, bowler reacting to turned down appeals and a much LARGER variety of these is an easy way to create similar atmosphere, without getting bogged down by specific sounds of players saying things to egg on a player.
...comes to down a less-is-more approach. If you have a bigger variety of crowd noises, bigger variety of player reactions/animations then you're getting closer to the "feel" of these events mattering in the context of a game. Having the wicket-keeper chirp away behind the stumps, while cute, isn't necessary if there's a better variety of player/crowd and in-game cinematics to tell the same story with the appropriate commentary to support it.
Comes back to that game experience Chief keeps talking about, if you FEEL like the game you're playing is realistic and matters, then little things like the wicket-keeper "saying something" become less important.
All that being said, some "gasps" or "oooohs" from the wicket keeper on specific occasions would suffice to create that real-life experience. Having a keeper saying "good delivery" or "that was close" in a billion different accents and iterations is more complicated and therefore, unnecessary.