Clowney arrived underweight and eager, but the Cowboys staff held him back, demanding massive muscle gain before he hit the field.
Dallas Cowboys veteran defensive end Jadeveon Clowney will look back on the 2025 season as one where he proved he's still got it.
And he's got the Cowboys training staff, in part, to thank.
Clowney would lead the Cowboys in sacks with 8.5 as he developed into a key weapon for Matt Eberflus' defense down the stretch.
Signed off the couch, Clowney's first game came in the 40-40 overtime tie with the Green Bay Packers. But he was signed weeks earlier in September.
So why didn't he play straight away after he told everyone he was ready to go?
Well, we now we have an answer.
“When Clowney first came here and signed, he was like let me play, I'm in shape, and this medical staff and training staff said no,” our own Mike Fisher said. “I don't know if he liked it or not. This is thumbs up on the Cowboys’ staff. He played at like 250 pounds over the course of the season.
"He showed up here at 228 and said, 'Let me play.' This staff said, 'You're too light. It's not that you're out of shape, fat. You're out of football shape in terms of what's going to be needed of you.”
OK, that makes sense. So they waited and worked.
But then Fish elaborated on what Clowney did to ensure he would be a weapon for the defense.
And it wasn't a case of running sprints or diving into the playbook; Jadeveon got to work, and make the changes Dallas wanted to see from him.
"He put on like 20 pounds of muscle or something," Fish added. "Ate a cheeseburger, ate a protein bar, and got in the weight room. I know it sounds unbelievable, but this is what I'm told.
"He put on 20 pounds in like two and a half weeks. It speaks to something really good about Clowney, how much he wanted it.
"It speaks to the Cowboy medical and training staff, too. They could have said, 'Fine, we need somebody to sack somebody,' and they didn't. They held him back for his own good. And obviously, it paid off.”
Now, the Cowboys have a decision to make on Clowney as he is a free agent coming off a season where he showed exactly what he can bring to this defense.
And that was without a full training camp, mind you.
Both sides want a reunion.
Imagine what the veteran could do if he's given months to get physically ready instead of a couple of weeks?