While he insisted that Warner had no idea what Trott was going through when he made those comments, Lehmann confirmed that he has spoken to the left-hander regarding his conduct.
Lehmann told reporters: "I have spoken to David, and we have dealt with that in-house. He understands where the line is. I think he said himself he crossed the line. We know where we can go to a certain extent.
"If you cross that line, obviously the ICC take over - and Cricket Australia. We want to play that brand that is quite hard and aggressive, as we always talk about - but not cross the line, play it fair.
"Obviously, we didn't know what was going on with Jonathan Trott - and that certainly won't be talked about in this Test match at all. We wish him all the best in his recovery... Jonathan Trott, we're not talking about this Test match."
The second Test is scheduled to get underway on December 5.