LAS VEGAS – Manny Pacquiao acknowledged Wednesday that he isn’t sure if this will be the last fight of his celebrated career.

A victory over Yordenis Ugas on Saturday night likely will encourage the 42-year-old Pacquiao to keep boxing. If the favored Filipino southpaw indeed defeats Ugas in their fight for the Cuban champion’s WBA “super” welterweight title and remains an active boxer, Pacquiao would want to continue testing himself against elite opponents in the 147-pound division.

Pacquiao would welcome rescheduling his showdown with Errol Spence Jr., his original opponent Saturday night, or revisiting a much-discussed fight with Terence Crawford. The ambitious senator discussed those possibilities following a press conference Wednesday at MGM Grand Garden Arena.

“As long as I’m still in boxing,” Pacquiao said, “I’m open to and willing to fight Terence Crawford, Errol Spence or anybody – the best.”

MGM Grand’s sports book lists Pacquiao as more than a 3-1 favorite to beat Ugas, who replaced Spence on less than two weeks’ notice due to Spence’s eye injury. Spence underwent surgery August 11 in Dallas to repair a damaged right retina that was detected two days earlier during an extensive eye exam in Las Vegas that the Nevada State Athletic Commission required for licensure.

Even if Pacquiao were to upset Crawford (37-0, 28 KOs), who owns the WBO welterweight title, or Spence (27-0, 21 KOs), the IBF/WBC champ, the legendary Pacquiao thinks he’d have a tough time topping what he considers his crowning achievement in December 2008.

“The greatest victory is the De La Hoya fight,” Pacquiao said before reiterating his willingness to face Crawford and/or Spence. “You know why? Because I came from 135 to 147. That’s unusual. I mean, not many boxers can do that. I mean, from 122, 126 to 135, and then moving up to 147 – what?”

De La Hoya, then 35, was a heavy favorite to beat a 29-year-old Pacquiao, a significantly shorter, lighter fighter who moved up from the lightweight division to welterweight for the chance to box “The Golden Boy” in an HBO Pay-Per-View main event. Pacquiao dominated De La Hoya, who didn’t answer the bell for the ninth round at MGM Grand Garden Arena.

De La Hoya retired after his lopsided loss to Pacquiao.

Pacquiao (62-7-2, 39 KOs) and Ugas (26-4, 12 KOs) will headline a FOX Sports Pay-Per-View show from nearby T-Mobile Arena. That four-fight telecast is scheduled to begin at 9 p.m. EDT/6 p.m. PDT and costs $74.95.

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