Boston Celtics rookie Jayson Tatum is already thinking about the most daunting task for any player in the NBA: guard LeBron James.

The Cleveland Cavaliers superstar has apparently been entering Tatum's thoughts a lot already, with the rookie envisioning the matchup that may take center stage in the Eastern Conference Finals.

It's one thing for it to go good in your head and something entirely different to make it happen on the floor.

To be fair, the matchup is far too much for Tatum alone and he is not expected to be an equal to The King anytime soon. Tatum may be an important part of the Celtics rotation this season, but will probably start by coming off the bench, leaving the checking of LeBron up to guys like Gordon Hayward and Jaylen Brown who have a bit more experience.

This year's No. 3 overall pick has impressed already in the summer league and also the preseason. His offensive repertoire appears to be more advanced than the average rookie and with his confidence not lacking, Tatum could be poised for a big year.

Defensively is still a bigger question for the rookie, like with any youngster so there are no expectations he could actually be up to guarding LeBron well. But Celtics fans might be happy he's already thinking about it.