SANTA CLARA >> Christian McCaffrey is yesterday’s news. So are the 49ers.

McCaffrey has long used slights both real and imagined as fuel for his insatiable appetite for work and preparation.

A year ago, McCaffrey was the reigning NFL Offensive Player of the Year and awaiting a late June wedding. Now he’s an aging, broken down running back awaiting fatherhood.

“I like the mentality we have and I like the narrative going around,” McCaffrey said Tuesday as the 49ers began their offseason program. “That’s the kind of stuff you can prove them right or prove them wrong. We have a committed team that’s ready to jell and realize it’s going to take all of us. That’s how it should be, showing up. I’m excited.”

Instead of McCaffrey making life miserable for opposing defenses, it was Philadelphia’s Saquon Barkley. Instead of being the key that unlocked the 49ers’ offense under Kyle Shanahan, McCaffrey introduced the fan base and media to the term “bilateral Achilles tendinitis.”

It took a trip to Germany and eight weeks of the season to get on the field, and then three games where he didn’t look anything like the player who was one of the NFL’s most versatile threats since his arrival by trade from Carolina on Oct. 20, 2022.

Nobody is sure how it happened or why it happened, although McCaffrey’s father, Ed, suggested on Ross Tucker’s podcast last October that his son had overtrained.

By the time McCaffrey finally began to look like himself last Dec. 1 in Buffalo, with seven rushes for 53 yards, he tore the posterior cruciate ligament in his right knee. He was done for the season, playing in four games with 50 rushes for 202 yards and 15 receptions for 146 yards.

And no touchdowns.

This is the same guy who in his first 37 games with the 49ers including the playoffs, had 745 touches (rushing and receiving) for 4,300 yards and 39 touchdowns.

Which of course leads to speculation that McCaffrey, 28, has hit his expiration date as a premiere running back. If so, he wouldn’t be the first at a position where players treat their bodies as if it were a demolition derby.

McCaffrey didn’t need surgery and has hit the ground running in a way he didn’t a year ago as he awaited a two-year, $38 million contract extension. He said he has no restrictions.

“It’s been such a smooth process, a lot of hard work,” McCaffrey said. “As soon as that injury happened in Buffalo, my goal was not to miss a day of OTAs, be back ready to go with nothing hindering me and that’s where I’m at.”