Question: If perchance the pope will persist in this direction, what will you do?Cardinal Burke: I shall resist, I can do nothing else. There is no doubt that it is a difficult time; this is clear, this is clear.
Read the rest here.
Note: The source is a French television interview via a website affiliated with the SSPX. Still, unless the Cardinal was seriously misquoted, I can see no way to interpret this other than as a direct warning to the Pope.
See also Fr.Z's take.