IBF welterweight champion Errol Spence (22-0, 19 KOs) is less than a week away before his first world title defense.

This coming Saturday night at the Barclays Center in Brooklyn, Spence will defend his belt against former world champion Lamont Peterson in the main event of a Showtime televised card.

It will be Spence's first bout since capturing the IBF title last May, when he traveled to Sheffield and stopped Kell Brook before champion's hometown crowd.

Spence is very eager to unify the division - and the first target on his list is WBC, WBA welterweight champion Keith Thurman.

"I would say that Keith Thurman is the most proven, because he beat Shawn Porter, he beat Danny Garcia, he has two of the belts. He's the most proven, so he might be the hardest one [for me to beat]," Spence told Kevin Iole of Yahoo Sports.

There is a lot of hype regarding Terence Crawford's move to the welterweight division.

Crawford unified the entire junior welterweight division in 2017, and now makes the move to 147 with the goal of doing the same. He starts his journey on April 21, when he challenges Jeff Horn for the WBO welterweight title at the T-Mobile Arena in Las Vegas.

At the moment, Spence is not really sure as to how big of a problem Crawford will be at the weight. He will have a better idea once Crawford has his upcoming fight with Horn.

"Terence Crawford has a lot of skill, a lot of ability. It will be interesting to see how he carries his power, how he carries that boxing ability, his physical strength, to 147," Spence said.

"It will be interesting to see how he does against Jeff Horn, who's kind of gritty fighter like Shawn Porter. He's a little bit [like Porter] but not as physical and not the same athleticism. It will be interesting to see how he does with that test."