As msltank noted this is an old question, so the original poster will probably not see any of these responses. However, questions about scar tissue in muscles and tendons are quite common.
MichaelZ34 asked why scar tissue could not just be cut out with surgery. As he had seen professional athletes having surgery for scar tissue problems. Unfortunately, surgery (controlled trauma) causes scar tissue. (All tissue, except bone, heals by creating scar tissue.) Depending upon how much scar tissue a person's body makes, surgery could actually make matters worse.
When surgery for scar tissue is performed, it is usually on a very discrete nodule of scar within a tendon. This discrete nodule is usually delineated by an MRI. The normal tendon is carefully dissected from around the scar tissue, then, as much as possible, it is removed without causing any further damage, and the normal tendon sutured to close down the defect. Widespread or diffuse scar tissue cannot be removed, nor can scar tissue that has become a supporting structure.
Patients often feel that they should be treated just like a professional athlete. However, when someone is making hundreds of thousands of dollars a game, for his/her athletic talents, a higher risk to benefit ratio is often accepted.
In the original poster's situation, his MRI was negative for a discrete area of scar tissue. That is the most likely reason surgery was not considered feasible. Unfortunately, it seems that today, many people are willing to undergo a dangerous procedure for an easy, quick fix (or what they perceive as easy and quick). As msltank noted, some types of physical therapy can be tried. They are usually more successful earlier on, but can be attempted late. Deep friction or cross friction massage may help. Ultrasound and iontophoresis (+/- corticosteriod) can also be tried. Long, sustained stretching can sometimes produce favorable results. However, the thing that usually helps the most, and patients hate, is a change in activity. Unfortunately, if all else fails, that sometimes becomes a reality.
Anyone with this type of problem should discuss it thoroughly with his/her healthcare providers. It is a difficult problem to treat and every case is different.