Play video content Exclusive 12/13/19 TMZSports.com

Ohio State superstar Chase Young -- the projected #1 overall pick in the 2020 NFL Draft -- says he's not thinking about declaring for the draft and the "plan" is to return to school.

... But you know what they say about plans. They change.

TMZ Sports spoke with the Heisman finalist in NYC on Friday before Saturday's big ceremony ... and, despite the MASSIVE contract he could have come April, Young says that's not on his mind.

Young -- a 20-year-old junior -- has been a dominant, uncontrollable force on defense for the Buckeyes this season ... racking up 16.5 sacks (a school record) despite being suspended 2 games.

So, yeah, whoever sits at the top of the draft is gonna want to either take Young or his old teammate/LSU sensation Joe Burrow ... but it sounds like the Bucks could come out winners. Maybe.

We also talked to Young about the upcoming Fiesta Bowl matchup with Clemson ... and he sounds ready to go.