You don’t need to say anything to the batsman. e.g. Leave mid wicket/ cover/ backward point vacant and suggest to you Captain/ bowler in an understated way that it would have to be a serious/ risky shot to penetrate that area. Test their ego. Michael Vaughan did it to Australia in 2005 by having a sweeper on the leg and off boundaries so a Martyn/ Hayden etc had to settle for 1 instead of 4. It worked without words.
If you have to speak suggest to a team mate that his grip or stance looks odd ( batsmen sometimes take things like that to heart). Sometimes it is a simple as that and no one gets angry. Just my experience.
Simply Excellent advice, thanks.
Normally I only have fielder deep straight mid wicket, to entice cross shots to square leg area.
Think I'll need to do that more often, to leave point etc vacant!
Yeah, v grip thing will make them think 😀😀!