Danny Garcia may not have been the most interested observer of last weekend’s Jeison Rosario-Julian Williams bout, but he should have been, especially at 1:37 of the fifth round, when Garcia’s fellow Philadelphian was upset by Rosario.

It’s not a local Philly thing, not a situation where Garcia lost a prospective big fight. Instead, it was a warning, a sign to the former two-division world champion that “stay busy” bouts or mandatories against unheralded foes can be more dangerous than any SuperFight.

For Garcia, his Barclays Center main event against Ivan Redkach on Saturday is expected to be the prelude to a showdown later this year that is infinitely more lucrative against either Errol Spence or Manny Pacquiao, and “Swift” hasn’t shied away from talking about such a matchup in the lead-up to his weekend’s date in Brooklyn.

"I feel like my style is dangerous for both Spence and Pacquiao," said Garcia. "For Errol, I see he likes to stand in front of his opponents and he isn't the hardest guy to hit. With Manny, I feel like my counterpunching and style would also be hard for him. So, I like my chances against both of them."

More importantly, the 31-year-old likes the idea of being back in a big fight. Sure, headlining a Showtime card is nothing to sneeze at, and he’s been the main attraction each step of the way since his losses to Keith Thurman and Shawn Porter, in 2017 and 2018, respectively. But Redkach is not Spence or Pacquiao, even though Garcia is saying all the right things about his foe.

“We picked Redkach because he's dangerous and we knew he'd be tough,” he said. “I'm definitely not overlooking him. I'm training hard for this fight. For me, this is a big fight. If I overlook him, it could ruin everything. I want to show everyone I'm still one of the best pound-for-pound fighters in the world.”

Saying something and doing something are two different things, though, and as history showed when Zab Judah lost to heavy underdog Carlos Baldomir in 2006 only to get a Floyd Mayweather fight three months later, a loss this weekend wouldn’t necessarily get him tossed from the Spence or Pacquiao sweepstakes. But it would take the shine off a fight that could put Garcia back in the pound-for-pound conversation, a place he may not have seriously been in since he defeated Lamont Peterson in 2015 to improve to 30-0.

Following that bout, Garcia has gone 5-2, but the wins have been against a mix of fighters on the tail end of their careers (Paul Malignaggi, Robert Guerrero, Brandon Rios) or tailor made for him stylistically (Samuel Vargas, Adrian Granados), none of which should have prepared him adequately for Thurman or Porter.

Yet when he did enter the ring against those fellow elites, there are plenty of folks who can make a case for Garcia getting the decision in each defeat. If he does beat either Thurman or Porter or both, Ivan Redkach is not his opponent this weekend, but that’s the fight game, and the 33-year-old Ukrainian will be the man opposite Garcia in Brooklyn. Redkach knows what’s expected to happen, but he also knows a win will be a life-changing one.

“Danny made a mistake if he thinks this is a tune-up,” Redkach said. “I'm going to give everyone a great fight and we'll see what happens on January 25.”

Last June, Redkach upset Devon Alexander’s apple cart, knocking out the former world champion in the sixth round. It was a reminder that before an 18-0, 1 NC start to his career turned into a 23-4-1, 1 NC slate, Redkach was a rising star in the sport. Knockout defeats at the hands of Dejan Zlaticanin and John Molina, and decision losses against Tevin Farmer and Argenis Mendez took that descriptor away, and now he’s the B-side. And Garcia knows what people are saying, so he says what he needs to.

"We're just working hard and working smart,” Garcia said. “We're making the necessary adjustments for Redkach, specifically, but this is just another fighter in front of us. I noticed that he's really hungry. He obviously wants to win, and he's coming off of three solid victories. He has his confidence back now. I just have to be ready for whatever he brings to the table on January 25.

“I just have to be on my A-game and make no mistakes.”

Garcia may not need his A-game to beat Redkach, but he does need to be wary of the one mistake that can change the trajectory of his career. And so far, the words are the right ones.

"I'm just taking it one fight at a time," he said. "I've been that way my whole career. I know that you can't overlook anyone. I'm totally locked in on Ivan, and that's it.”

If Redkach turns into Jeison Rosario, the race for Upset of the Year will shift from Philadelphia to Brooklyn, and when it comes to Garcia getting what he wants later in 2020, that will be it. And he’ll have no one to blame but himself.

So call it a tune-up, or call it the most important fight of Garcia’s career. Swift’s decision will be the final one.