SANTA CLARA — Just like Fred Warner and so many other 49ers defenders, all Mykel Williams could do was watch as his rookie season came to an unsatisfying end this past January.

The former 11th overall pick has been unable to help this season, stuck on the Physically Unable to Perform list even as he has painfully close to the designation no longer applying.

“I’m going crazy. I’m losing my mind,” Williams said this week. “I’m ready to go. I miss playing ball. It’s been like damn near a year. … Knowing how banged-up we are, it’s just been killing me watching it transpire how it has been. I’m ready to get back on the field.”

There is still no official word from the 49ers on Williams’ status for the rematch of their 41-6 divisional round loss in Seattle. They opened his practice window last week and will be eligible to activate him from the PUP list for the first time this week, though it’s not required.

But the first-round defensive lineman kind of said the quiet part out loud when he was asked about how his offseason diet, training and rehab regimen would translate on the field.

“We’ll see Sunday,” he said. “We’ll see Sunday.”

Forget any gamesmanship that might have been thrown out the door.

That should be music to the ears of the 49ers and their Faithful.

No, they still won’t have Nick Bosa for at least another week.

But getting No. 98 back is the next-best thing to No. 97.

The 49ers never really got to experience the full package of what made Williams a consensus first-rounder coming out of Georgia before he tore his ACL in Week 9. He shared the field with Bosa for only three games, which accounted for 25% of the 49ers’ season sack total.

He’s never gotten a chance to play for Raheem Morris. But the 49ers defensive coordinator became plenty familiar with him as a draft prospect when he was head coach of the Falcons.

Morris saw exactly why Williams could be so valuable in this moment for the undermanned Niners front.

“He can play anywhere,” Morris said. “He’s kind of that spinner in a different way. He can go inside, outside, do different things like that. I’m not sure if he couldn’t stand up.” 

The potential pairing of Williams and Bosa on each edge is tantalizing to think about. But right now, the Niners need help anywhere they can get it. And Williams can fill just about any gap.

In the nine games he was on the field, the 49ers yielded only 3.5 yards per carry, an improvement of 1.2 yards per carry from 2024 and 0.6 yards per carry better than their eight remaining games last year.

But even Williams doesn’t believe that he showcased the best he has to offer as a rookie under Robert Saleh. He was responsible for only one sack and four pressures after racking up 14 sacks and 21 ½ tackles for loss in three years of SEC competition.

“I wasn’t happy with what I did out there, for real,” Williams said. “I know the type of player I am, and I don’t think I represented myself well on tape last year. … From the get off, to pad level, to hand usage — just developing and feeling comfortable in the defense.”

Should he play Sunday, he’ll make his return about 10 ½ months after going under the knife last Nov. 25. Bosa, who had the same procedure for the third time a short while earlier, was “great in my whole recovery,” Williams said. “I was leaning on him so much.”

Williams, a self-described sweet tooth, took his cues from the health-obsessed Bosa in more areas than one. He cut out his prized peach cobbler and ice cream in favor of protein shakes.

Yes, the “best shape of his life” is a tired cliche, especially for a 22-year-old. At the very least, though, Williams is leaner with no loss of muscle and for the first time in years fully healthy.

Even Morris joked that he came to believe Williams was slow scouting him at Georgia because of an ankle injury that hampered his final season. He was a borderline decision to go on PUP at the end of training camp, but the 49ers wanted to make sure he was 100%.

“We did what we thought was in his best interest and our team’s best interest to give him some extra time,” general manager John Lynch said in his weekly appearance on KNBR. “I think he was just scratching the surface last year of what he can be.”

Williams didn’t even count among the six of the 10 defensive linemen from the 49ers initial 53-man roster to get hurt in the season’s first two weeks. Things are beginning to look up with rookie edge rusher Romello Height back in action last week, Williams expected to join him this week and Bosa not far behind, seen working off to the side in practice Thursday.

The defensive line is sure to be high on the list of Lynch’s priorities ahead of the Nov. 11 trade deadline, and he said they “will not hesitate to improve this team if we can.”

For now, Williams — and eventually Bosa — will have to do.

“We’ve had to patch it together,” Lynch said. “Now we’re getting Mykel back.”