"I most definitely can knock Logan Paul out, without a doubt."
That's "Suga" Rashad Evans throwing down the gauntlet ... challenging 26-year-old YouTube star turned pugilist Logan Paul to a BOXING match.
41-year-old Evans -- inducted into the UFC Hall of Fame in 2019 -- hasn't fought since taking an L to Anthony Smith at UFC 225 in June 2018.
But, in case you forgot ... Suga's beat Rampage Jackson, Chael Sonnen (still undefeated), Dan Henderson, Forrest Griffin, Michael Bisping and Tito Ortiz -- just to name a few.
Back to Logan ... rumors have been swirling that a fight between LP and Evans could be in the works -- and Rashad says he's 100% down to scrap.
"I don't know what [Logan's] looking for, for his next match. But, I'm gonna tell you right now what he needs. What he needs is a taste of 'Suga.'"
Of course, Paul is only a few weeks removed from his exhibition fight with 44-year-old Floyd Mayweather ... a bout that went the full 8 rounds.
Mayweather wasn't able to drop Logan -- who was about 50 lbs. heavier than Floyd -- something Evans says will NOT be the case if they fight.
"I'll tell ya what, [Logan] comes at me, he's gonna get put to sleep."