Mykel Willams’ rookie NFL season was cut short when the 49ers defensive lineman sustained a torn ACL in Week 9, just six games after veteran Nick Bosa went down with the same injury.

The 21-year-old Williams spoke to reporters Monday as the 49ers cleaned out their lockers, describing what he has gone through after the most severe injury of his young career — and how Bosa, who now has torn his ACL three times, is helping him through it.

“I ain’t going to lie to you, it’s been hard,” Williams said. “It’s been hard dealing with something like this, of this significance. Probably the biggest injury I’ve ever had, and then just the time table that it takes [to return]. Then missing all the important games that I’m missing, and just the events that I’m missing with the guys out there. It would have been nice to be a part of it.”

Williams, San Francisco’s first-round pick in the 2025 NFL Draft, was just one of several high-profile injuries the 49ers overcame en route to an improbable NFC playoff run, which ended with a 41-6 divisional-round loss to the Seattle Seahawks on Saturday at Lumen Field.

But sidelined right along with him was fellow defensive end Bosa, who already served as a mentor for the young lineman and continued that role throughout their rehab.

“It helped me a lot, man,” Williams said of leaning on Bosa. “Bosa has been extremely helpful. He’s like a real big brother. He looks out, he comes in, checks on me, sits down, eats lunch with me, talks to me, asks me about my knee, asks me how I’m feeling, like where I’m at in the process. …

“I’ll be feeling more comfortable leaning on him and asking him for stuff versus a lot of other people. So I just come to Bosa and lean on him, and ask him because he’s been through it. He knows exactly what it felt like and how to how to move on.”

Before tearing his ACL in the fourth quarter of the 49ers’ 34-24 win over the New York Giants on Nov. 2, Williams had recorded one sack, one fumble recovery, 20 combined tackles (four for a loss) and three quarterback hits as one of three defensive linemen drafted by San Francisco before the season’s start.

The 49ers relied heavily on the rookies in a year where youth was their MO, and coach Kyle Shanahan was pleased with what he saw from Williams as he adjusted to the NFL and dealt with numerous injuries, not just the ACL tear.

“We knew we needed a starting defensive end, that’s what our goal was, and we also felt we needed some pass rushers who could play inside on third down,” Shanahan told NBC Sports Bay Area’s Matt Maiocco on “49ers Game Plan” after the injury.

“We also wanted to bring in a good person with high character, high football character to our building. All he has shown us right away is the type of guy he is. Sometimes you got to see guys go through adversity to see how they’ll grind and things like that, we got to see that.” 

Williams showed the 49ers in a short time that he can be the player they need, and now, he’ll continue studying film and learning from teammates like Bosa in an effort to return even better than before.

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