Philip Rivers' decision to unretire five years after his last snap to join the Indianapolis Colts prompted Tom Brady to deliver a pointed joke about the quarterback's comeback.

"Who retires and then unretires and then is ultimately going to retire again? Who does that? That's ridiculous for Philip to do that," Brady quipped about the 44-year-old Rivers during an appearance Thursday on "The Herd."

The irony wasn't lost on anyone. Brady retired from the Tampa Bay Buccaneers in February 2022, then unretired just 40 days later. After playing the 2022 season with Tampa Bay, he retired for good and now serves as FOX Sports' lead NFL analyst.

Still, Brady's jab at Rivers raises a larger question: Could Brady himself still play quarterback in the NFL at 48?

Brady Says He Could Play—But Won't

When asked directly if he could lead a team to multiple scoring drives with sufficient system knowledge, Brady didn't hesitate.

"Yes, I certainly could," he said. "I think the answer for me would be yes. I'm not allowed to anymore because I'm a minority owner of the Raiders, so I can't unretire."

Brady backed up his confidence with hard numbers. When he retired after the 2022 season, he was still performing at an elite level—4,694 passing yards, 25 touchdowns and seven interceptions while leading the Buccaneers to the NFC South title at age 45. The previous year, he threw for over 5,000 yards and finished second in MVP voting.

Rivers Will Prove the Point

With Brady's playing days barred by his Raiders ownership stake, he'll watch Rivers attempt to prove that quarterbacks can succeed in their mid-40s.

"I'm very excited to watch Philip play," Brady said. "If he's out there, it's just very cool. It speaks to how much he loves the game and really what he's able to do still."

Rivers is currently on the Colts' practice squad, but Indianapolis head coach Shane Steichen hasn't ruled out a starting role for the former Charger in Sunday's matchup against the Seattle Seahawks.

Mental Game Matters Most

Brady dismissed the chatter about athletic conditioning, arguing the quarterback position depends far more on what happens between the ears.

"This game is about, for the quarterback, from the neck up," Brady explained. "We used to have a saying at Michigan, 'The mental is to the physical as four is to one at the quarterback position.' That doesn't really go away. Do you still have the physical ability to still do it—take the hits, make the throws, the drops, buy a little time in the pocket?"

"If Philip has been practicing those things, then we're all going to see it on full display in Seattle on Sunday afternoon."