Shawn Porter can’t differentiate between who gave him the tougher fight between Errol Spence and Keith Thurman but is confident who would win should they ever collide.

The former two-time welterweight titlist came up just short in separate fights with the two while both were undefeated champs. That status still remains for Spence (26-0, 21KOs) who is now a unified welterweight titlist following a hard-fought 12-round split decision win over Porter last September in Los Angeles, California.

The loss snapped a four-fight win streak for the now 32-year old from Las Vegas by way of Akron, Ohio, whose previous loss came in a close unanimous decision at the hands of Thurman (29-1, 22KOs; 1NC) in their June 2016 thriller from Barclays Center in Brooklyn, New York.

Porter suffered a knockdown in the 11th round versus Spence, when a left hand forced his gloves to touch the canvas. He remained upright for all 12 rounds versus Thurman but was visibly shaken by a left hook in round four and nearly dropped by the same shot in the 10th round.

“Both guys caught me with one punch. One big punch. I don’t know who is the harder hitter,” Porter (30-3-1, 17KOs) noted when asked to choose between the two during a live chat on the Premier Boxing Champions (PBC) Facebook page. “In the ring, when the adrenaline is going and you’re focused on your mission, you’re not thinking about that.

“I really don’t know who hits harder.”

Thurman was out of the ring for 11 months by the time he faced Porter, then sat out another nine months before outpointing Danny Garcia to unify two welterweight titles in March 2017. That was followed by a 22-month hiatus to repair multiple injuries, having since fought twice in 2019—a harder-than-expected 12-round win over fringe contender Josesito Lopez last January and a narrow points loss to legendary Filipino southpaw Manny Pacquiao (62-7-2, 39KOs) in their title consolidation clash last July.

From Porter’s view, the version of the Clearwater, Florida product he faced nearly four years ago no longer exists—and doesn’t figure the current day version to stand much of a chance should he face Spence at some point.

“I’d pick Spence,” Porter insists without hesitation. “Keith Thurman has been out of the ring too much. I don’t think he’s the same fighter he was when I fought him. I’d have to go with Spence.”

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox