To his credit, Keith Thurman is keeping a promise he made prior to the start of 2019, where he guaranteed that 2020 will be the year he returns at full strength.

Of course, his belief of 2019 serving as a ‘get-back’ year didn’t quite pan out as expected.

“Obviously this hasn’t been my greatest year,” Thurman (29-1, 22KOs) quipped during a recent guest host appearance on Fox Sports’ Inside PBC Boxing. The special Sunday afternoon edition of the hit studio series was designed to promote the Sept. 28 Fox Sports Pay-Per-View headliner, a welterweight title unification clash between Errol Spence and Shawn Porter, but also addressed Thurman’s recent surgery to his left hand.

The procedure took place earlier this month, which was first reported by Yahoo! Sports’ Kevin Iole. The 30-year old Clearwater, Fl. native confessed that he went into both of his bouts in 2019—a narrow win over Josesito Lopez in January and a heartbreaking loss to legendary Manny Pacquiao this past July—still feeling the effects of injuries sustained years ago but which he hoped had healed well enough to finally return to the ring earlier this year.

“I’ve been through so much, with the elbow surgery the inflammation that was in my hand,” Thurman noted to Fox Sports host Kate Abdo. “As athletes, we suffer from time to time, but we endure it.

“The arthritic issue with the metacarpals in my left hand have been there for a year-and-a-half. I had it in the Mann Pacquiao fight, I had it in the Josesito Lopez fight.”

Thurman’s aforementioned win over Lopez marked his first piece of ring action since beating Danny Garcia in a March 2017 pairing between unbeaten welterweight titlists. Efforts to return at any point in 2018 were only offset by additional injuries, before returning earlier this year. The idea was to regain his bearings through a couple of mid-level wins before setting his sights on the division’s elite—Errol Spence, Terence Crawford, Pacquiao and even a rematch with Porter, whom he defeated in a memorable June 2016 clash.

The unexpected opportunity to face Pacquiao this summer obviously sped up that process. It was a chance Thurman had to take, as the 40-year old Filipino southpaw would’ve selected another had he not answered the call. Doing so, however, meant coming in with 100% of whatever he had.

“If I had to put a percentage on it…  I’d say at least 50%,” Thurman admitted to how much his lingering injuries have affected each of his two performances in 2019.

Following what he hopes is successful surgery earlier this month, a mid-spring 2020 ring return is now in the works—this time, most certainly not any sooner than necessary.

“I had to have surgery about two weeks ago. What they’re trying to do is fuse my bones together,” Thurman explained of the efforts to restore him back to full health. “It’s a surgical process. It’s going to take about six months to heal. I plan to be back in the ring next May, early June. It’s just a lot of pain.”

Jake Donovan is a senior writer for Twitter: @JakeNDaBox