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.’’.