Joakim Noah’s demise didn’t just happen.

There were concerns about what was going on with the big man the past few years.

According to a source close to the situation, once the veteran center became a part of the in-season “Jen Swanson program,’’ there wasn’t enough focus on the strength aspect of his game.

The source said Noah would have a good offseason with his own trainers, but once he rejoined the Bulls in training camp the focus was more on stretching rather than maintaining his strength.

“Jo was undersized as it was on most nights,’’ the source said. “His strength was deceiving. It was the equalizer.’’

Not that all of Noah’s injuries can be directly related to that, but the Bulls did fire the director of sports performance in Swanson earlier this week.

The bigger question facing the team now, however, is will they even have the chance to see if Noah can relocate his game for this upcoming season?

Noah is an unrestricted free agent, coming off a year in which he lost his starting job, got into a he said, he said with his first year coach Fred Hoiberg, and was then lost for the year by mid-January when his left shoulder betrayed him.

Coming off two major surgeries in the last three years, the 31-year-old isn’t even close to resembling the player that was the Defensive Player of the Year and finished fourth in the MVP voting back in the 2013-14 campaign.

He does bring a toughness that this Bulls team sorely lacks, however, and that’s why they have already been talking to Noah about re-signing.

“Anyone who has been around us, anybody who has spoken to either Gar [Forman] or I about Joakim, they know how we feel about him, he represents a lot of things that we believe in,’’ VP of basketball operations John Paxson said. “To me, he’s one of the most genuine people I’ve ever been around in this business, as far as people go. So we have an affinity for Jo. But we’ve got to talk, we’ve got to see where it goes.’’

WHAT’S COMING BACK

Cristiano Felicio – Over the final seven games of the season, the 6-foot-10 rookie averaged 7.9 points and 5.9 rebounds per game, but more importantly showed an athleticism that perfectly fits into what Hoiberg wants from his center both offensively and defensively.

WHAT’S DEPARTING

Pau Gasol – The Bulls expressed an interest in re-signing the big man in March, but the feeling wasn’t mutual by the end of the season. Gasol grew tired of the circus atmosphere and will look elsewhere after he opts out of his deal.

Noah – The Bulls will try to persuade the veteran to return, and while there is a strong love for Chicago, Noah’s pride was hurt in the entire benching drama. It will be a tough sell job to repair that bridge.

WHAT’S OUT THERE

As crazy as it sounds, the one free agent that fits what Hoiberg wants is Dwight Howard. The veteran was expected to opt out of his contract, and would give Hoiberg one of the best rebound-outlet big men in the game to get his quick-paced offense jumpstarted.

If the Bulls added Howard, however, they better also look to bring in a player with a warden mentality to make sure the locker room stays focused.

THE DRAFT

Not the year to be thinking center in the draft, especially sitting at No. 14 like the Bulls are. No, free agency is the ticket to be reloading at this spot.