Too young, lacks experience, not enough power ... are all criticisms Xander Zayas has heard leading up to his huge fight with Jaron "Boots" Ennis, but the boxing star says he's unfazed, promising a big performance next weekend in Brooklyn!

The 23-year-old unified super welterweight champ chopped it up with TMZ Sports ahead of the June 27th scrap at Barclays, pitting the two undefeated fighters against each other ... and Zayas admits the high stakes make this one more special.

"I feel like every fight is important and I've always given that importance to every fight. Obviously, this one is a bit different because you have undefeated fighters that are well known in the boxing world and in the athletic world so I feel like it's exciting," Xander told us.

"A lot of fans want to see it, they want to watch this fight. Two hungry lions that are looking forward to keep making legacy and keep making history, so I'm really excited for it!"

Both fighters have unblemished records. Boots is 35-0 with 31 KOs, meanwhile, Zayas is 23-0 with 13 KOs.

Despite all his accomplishments, Xander is a heavy underdog (+375) ... but he says being doubted is nothing new.

Xander tells us, "Man, that's always been the case in my life," he explains, "I've always faced guys that are older than me, that have more experience than me, and I'm always in my head and in a way the underdog because they always say, 'Oh the young guy doesn't have that much experience.' Until we get in the ring, so at the end it comes down to June 27."

And, when the sun rises on the 28th, Xander says one thing will be clear.

"This is the fight. After I win June 27th, there's no doubt, I'm the biggest name at 154 [lbs.] I've been saying it throughout the years. Now I have to prove it

Check out the interview with Zayas ... who also talks about his relationship with Terence "Bud" Crawford, and whether there could be any special celebrity guests who come out for the event (remember, Xander was part of Bad Bunny's Super Bowl halftime show!).