Jermaine O’Neal’s torn wrist cartilage (wait, he tore cartilage?) should be healthy enough to play in Tuesday’s season opener against the Miami Heat. But he still doesn’t know the Celtics’ plays very well. (ESPN Boston)

Celtics center Jermaine O’Neal, who has battled hamstring, back, and hand issues during the preseason, returned to practice Friday after a week of inactivity and participated in the full session. Sporting a small brace over his left wrist, he revealed he tore cartilage there while taking a charge in the first quarter of exhibition win over the Toronto Raptors last Friday. 

“I wanted to get back at it and it felt pretty good today,” said O’Neal. “I got a little wrap to keep [the wrist] stable, but I’m not worried about it.”

O’Neal said he expects to be ready for Tuesday’s season-opener against his former team, the Miami Heat, but coach Doc Rivers noted he’s got some catching up to do in terms of learning the system. O’Neal, who missed four preseason games and many practices, spent extra time after Friday’s session running through offensive sets with a hodgepodge of teachers (Rajon Rondo, Armond Hill, Ty Lue) and other new faces (Luke Harangody and Von Wafer).

The lesson, as always: Jermaine O’Neal’s body is as reliable as Tony Allen’s jumper, although not quite as ugly.

On a more Turkish note, Semih Erden’s shoulder has been bothering him. The injury train continues.