The good doctor came on "TMZ Live" Monday, where he revealed he has a sit-down scheduled with DT in the near future -- for a special called "Trump Verdict: A Judicial Travesty" that's airing Thursday.

Phil tells us that as part of their convo, he'll be encouraging Trump to steer clear of playing tit for tat if he wins the election in November ... cause it could spell the end of the country as we know it.

DP tells us instead of a cycle of retribution and revenge -- which is kinda DT's thing these days -- America is in dire need of a leader focused on addressing the serious public issues at hand ... and he says he's going to tell Trump this when they talk later this week.

Phil's been forced to think about life with Trump as Prez again ... especially 'cause a focus group he conducted with his live studio audience aligned with the polls -- which showed most people's views on Trump haven't changed in light of his recent guilty verdict.

However, he tells us the focus group didn't come without some concerns -- giving an example of one person worried Trump being a convicted felon might make him choke when marking the ballot come voting season.

Right now, it looks like Trump's definitely feeling vindictive in the wake of the conviction ... as he's been publicly crying foul over last week's guilty verdict, calling it a sham and corrupt, while laughing off the idea of spending time behind bars as downright ridiculous.

Despite being the first U.S. president to become a convicted felon, Trump still boasts a rock-solid army of supporters, as seen by the uproar outside the NYC hearing -- making it evident anything can happen during the 2024 Presidential Election.