Detroit Lions fans received a sobering dose of reality this week when prominent NFL injury expert Dr. David Chao offered a concerning long-term outlook on star safety Kerby Joseph. Speaking from Radio Row during Super Bowl week in early February 2026, the former team physician with 17 years of NFL experience and current head of Sports Injury Central shared his thoughts with Detroit Free Press beat writer Dave Birkett.

While Chao emphasized he was “rooting” for the 25-year-old All-Pro, his assessment painted a grim picture of Joseph’s knee injury, raising serious questions about whether the talented defender can fulfill his recently signed contract extension or even return to elite form.

Joseph, a former third-round pick who exploded onto the scene with a league-leading nine interceptions in 2024 (earning First-Team All-Pro honors), suffered a significant left knee injury during the 2025 season. The issue first surfaced in Week 4 against the Cleveland Browns on September 28, sidelining him after just six games played. Head coach Dan Campbell remained vague about the timeline early on, but Joseph was eventually placed on Injured Reserve in December, ending his campaign prematurely. Reports indicated he re-aggravated the problem upon attempting a return, forcing the Lions to shut him down for the year.

The latest concern stems from Joseph’s reported pursuit of non-surgical treatments, including stem cell therapy, to address the lingering knee problems. When informed of this approach during the interview, Chao did not mince words. “This one’s a little dicey, here. Once again rooting for him,” he said. “But articular cartilage is the holy grail. If you could reproduce or regrow articular cartilage, you would win the Nobel Prize, okay. It is the holy grail. It’s the tread on your tires. You can’t just get retreads or put new tires on it.

How do you replace the rubber on your tires? That’s the articular cartilage. Poor vasculature. Very difficult.”

Chao went on to explain that discussions of stem cells typically indicate damage has progressed beyond standard interventions like microfracture procedures. “Kerby Joseph, I don’t know the extent of his knee. But when you’re starting to talk about stem cells, that means you’re beyond even micro fracture,” he noted. “It’s not that. It’s very dicey.

I wish him the best, but this is not good news.” He described the odds of a full recovery as a “Hail Mary,” suggesting that even if Joseph returns in 2026, the chronic nature of articular cartilage damage could limit his durability, explosiveness, and longevity in the league.

Importantly, Chao acknowledged he had not reviewed Joseph’s medical charts or imaging personally—his comments were based on general knowledge of similar cases and the specifics shared during the conversation. This caveat has led some fans and analysts to temper the alarm, labeling the take as speculative or sensationalist. Others, however, see it as a realistic warning sign. In a position like safety that demands quick cuts, acceleration, and high-impact collisions, compromised knee cartilage can be career-altering—or career-ending.

Joseph signed a lucrative extension with the Lions prior to the 2025 season, reportedly worth around $86 million over several years, reflecting his status as one of the NFL’s top young defensive backs. The contract runs through at least 2029 in some reports, but Chao’s comments have sparked immediate discussions about whether Joseph can realistically play out its full term.

Salary cap implications loom large for Detroit heading into the 2026 offseason: with projected flexibility but major decisions on stars like Jared Goff, Jahmyr Gibbs, and others, an uncertain future for a high-paid safety could force tough choices, including potential restructures, trades, or even a post-June 1 designation if recovery stalls.

The Lions’ defense has already felt the absence. Without Joseph in 2025, the secondary struggled at times, and the team missed his ball-hawking instincts and physical presence alongside partners like Brian Branch (who also dealt with injuries). Branch’s own timeline was discussed in the same interview, with Chao offering more optimistic views on potential returns for him and tight end Sam LaPorta, but Joseph’s case stood out as particularly worrisome.

Fan reactions have ranged from panic to cautious optimism. On forums, social media, and Lions-centric communities, supporters expressed stomach-dropping concern: “This one’s scary—Kerby’s our tone-setter,” one wrote. Others pushed back: “Why listen to an ‘internet doctor’ who hasn’t seen the MRIs? Wait for official updates.” Joseph himself has remained relatively quiet, reportedly focusing on rehab and non-surgical options to avoid more invasive procedures that carry their own risks.

For now, the prognosis remains uncertain. Medical advancements in regenerative therapies like stem cells offer hope, but as Chao bluntly pointed out, true cartilage regrowth remains elusive science. Joseph, still young at 25, has time on his side, and the Lions’ medical staff will work tirelessly to get him back. A full offseason of targeted treatment could yield progress, potentially allowing a return for training camp in 2026.

Yet Chao’s words serve as a stark reminder of the brutal toll the NFL takes on players’ bodies. Kerby Joseph has already proven he’s one of the game’s brightest defensive talents—now the question is whether his knee will allow him to sustain that brilliance. Lions Nation watches anxiously, hoping for the best while bracing for the possibility that this injury could reshape both Joseph’s career and Detroit’s defensive future.