From Pacers.com:

As the Pacers open the regular season Wednesday in Toronto, they'll be without Danny Granger, who is out indefinitely with continued soreness in his knee.

"He's going to see some other doctors, get some other opinions and then we'll decide a course from there," Coach Vogel said after practice Tuesday.

A tendon in his left knee has bothered Granger dating back to the Miami playoff series last May. The pain mostly subsided and he thought it would be fine until he tweaked it again during summer workouts.

Granger was held out of the first five preseason games and finally saw the court for the final two games, though his minutes were restricted to 12 and 22, respectively. While on the floor, he never looked himself. Instead, he was timid and hesitated on every move. When he was open for a three, he hesitated and didn't bend his knee much on the release. There was also one particular play at Notre Dame against the Bulls, where Granger saw an opening and drove it in, only to throw it up quickly rather than powering up off his leg.

Last week after practice, Granger explained that he's fighting a different type of soreness, where he "has to stress through it and break up some of the scar tissue." He said the injury has been tough on him, as he had to fight through his own limitations. Most of all, he couldn't jump off his left leg.
From Monteith:

Granger, the Pacers' leading scorer the past five seasons, played the final two preseason games and appeared to be ready to start in Wednesday's season-opener, but was declared out indefinitely on Tuesday after experiencing more pain in his knee during Monday's practice. He has received one "second" opinion and is due for more feedback before a decision is made. At this point it appears the possibilities range from a short recovery period to surgery.
From LeCornrows:

Granger's return remains uncertain, but with the team on the road and the training staff still at least a day away from gathering all the info on the knee's status and deciding the next course of action, it doesn't seem like Granger will be back in the near term.
Can anybody give a decent explanation of what's going on here? Surely it's not just "break up some scar tissue" any more, or it wouldn't cause this delay. Right?