Errol Spence Jr. didn’t genuinely consider Mikey Garcia a serious threat to beat him.

Garcia surprised Spence by demanding their welterweight title fight, an ambitious move that required Garcia to move up from the lightweight limit of 135 pounds to 147. Spence is an even heavier favorite to beat Shawn Porter on Saturday night than he was against Garcia, but Spence still considers this a bigger bout because Porter is a true welterweight and owns one of boxing’s recognized 147-pound championships.

Spence expects the rugged Porter’s determination and toughness to make their fight more competitive than his 12-round domination of Garcia six months ago.

“I think Mikey Garcia is a real bigger name than Shawn Porter,” Spence said during a recent conference call. “But as a fan-friendly fight, or as an entertaining fight, I would say, you know, this fight with Shawn Porter is gonna be, I feel like, way more entertaining than the Mikey Garcia fight. I feel like the Shawn Porter fight, just because it’s a unification fight, being it’s a real fight, I feel like, you know, the Shawn Porter fight is bigger. But name-wise, I would say the Garcia fight was bigger.”

Spence-Garcia, which took place March 16 in Arlington, Texas, was a commercial success, despite the one-sided nature of an encounter Spence won by unanimous decision.

Their FOX Sports Pay-Per-View show reportedly drew about 400,000 buys. The card headlined by Spence-Garcia also attracted an announced crowd of 47,525 to AT&T Stadium, home of the Dallas Cowboys.

Spence is a native of DeSoto, Texas, a Dallas suburb. Garcia (39-1, 30 KOs) – a Mexican-American from Oxnard, California, who has won world titles in four divisions – also had a lot to do with the huge crowd assembling that night.

FOX Sports also will distribute the Spence-Porter card Saturday night from Staples Center in Los Angeles. Spence (25-0, 21 KOs), the IBF champion, is listed as a 10-1 favorite over Las Vegas’ Porter (30-2-1, 17 KOs), the WBC champ, by most Las Vegas and Internet sports books.

Spence was about a 4-1 favorite against Garcia, even though he owned significant size and power advantages over his challenger.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.