Top UFC middleweight Marvin Vettori has challenged YouTube star Jake Paul to a sparring session behind closed doors.
Vettori told Paul to put his "nuts on the table" earlier this month and promised the novice boxer he wouldn't go six rounds with him in sparring.
'The Italian Dream' is still dealing with a knee injury he suffered in his hard-fought win against Paulo Costa last October, but is hopeful of returning to the octagon soon.
The No.2 ranked middleweight has never boxed professionally, but has sparred with world titleholders such as super middleweight champion David Benavidez.
And Vettori said Paul can meet him at the Brickhouse Boxing Club in North Hollywood if he wants to a sparring session.
"I heard he doesn't wanna spar guys that give him trouble, so for one time you can come and test yourself, it's good," he told Mirror Fighting.
"If you can hang a little bit with me that shows you can step it up maybe in terms of an opponent and pick somebody pretty serious.
"So come on Paul, show up. I'm at Brickhouse, every Tuesday and Thursday, 10 am, whenever you want I'm right there.
"Show up, we close the doors, no cameras I'll make sure you look good and I'm not going to make you look like you're a bum. Come in and we'll train a little bit, I'll show you."
Paul has been called out by several UFC fighters since improving to 5-0 in his newfound boxing career last year.
'The Problem Child' has pleaded with UFC boss Dana White to let him box fighters who are under UFC contract, but White is not eager to work with him.
And Vettori challenged Paul to spar because he doesn't think the 25-year-old is "stupid" enough to fight him.
"I just wanna spar him and punch him a little bit, show him what's up. I wasn't really looking to fight him, I don't think he's that stupid," he continued.
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"Listen, I give him credit for what he's doing. To get into a complete different game and being able to pick the right fights."
Paul made a reported $40million from his three fights last year, later claiming the figure was even more than that.
And Vettori continued: "He's making good money. More than a lot of people in the UFC. I train in North Hollywood a lot for boxing, I'm at Brickhouse a lot of times and I know he's there a lot too.
"So show up and let's roll. I can give my opinion, maybe he's that good for real. I'm honest man, when somebody deserves respect I'm the first one to give that.
"But he keeps beating these bums up and I don't feel like he's deserving of my respect. He's fighting these guys that are horribly standing [up]."