Why would you warn someone away from doing something if you have nothing to hide and have done nothing wrong? Logic would dictate that Trump would go out of his way to help the investigators see anything they wanted.
And why talk of a pardon before he or anyone in his family or businesses have been indicted, let alone tried, let alone convicted?
On the Sunday talk shows, Trump's lawyers first said the West Wing was not talking about pardons, but even if they were, Trump could pardon whoever he wanted and claimed only the Supreme Court could decide if a President could pardon him or herself.
If the White House legal staff isn't even talking about pardons, why did Trump bring it up himself unprompted? Why are his lawyers talking up pardons at the same time they're denying anyone's talking about pardons?
Given Trump has brought up pardons, his lawyers might want to brief him about an important Supreme Court case decided in 1915 called Burdick v. United States. That decision established, when someone accepts a pardon, that's an admission of guilt (details here).
While legally anyone Trump pardons probably cannot be prosecuted in a federal courtr, does Trump actually think pardoning guilty members of his own family won't have any political repercussions for him?