The veteran center broke the third metacarpal bone in his right, snapping hand during the morning training-camp session. He'll have minor surgery this morning and may be lost for two weeks or more.
"I felt numbness in all four fingers," Sapolu said. "But when I shook it, there was a lot more shaking in there than just numbness."
"I've felt that feeling a thousand times before, but the difference was, this time I couldn't shake it off."
In his 14th year, the 35-year-old Sapolu is making the move back to center this year after two seasons at left guard. He expects to have the hand in a cast by early next week, but hopes to be playing with nothing more than a heavy tape job by the time the regular season opens against New Orleans on Sept. 1.
"For somebody my age, maybe it's better for me to come back fresh," Sapolu said. "We always say the veterans only need two preseason games anyway."
Sapolu injured his hand during a blitz drill, when defensive end Roy Barker stunted inside and Sapolu attempted to pick him up.
The only offensive lineman to start all 17 games for San Francisco in 1995, Sapolu will be back in the Bay Area Friday to have a screw inserted in his hand by Dr. Gordon Brodie.
In Sapolu's absence, fourth-year man Chris Dalman becomes the first-string center. Dalman hasn't started a game at center since December of 1994, but he'll start there when the 49ers entertain Denver in their first exhibition game Aug. 3.
If a cast should keep Sapolu from being an effective snapper for any length of time, he might be moved back to guard.
"To what extent he's out, we don't know," head coach George Seifert said. "He might play guard, or it's not inconceivable that he could snap with his left hand."
It's not inconceivable, because Sapolu is naturally left-handed. He has never tried snapping the ball with his left hand, but says he'll experiment with it when he returns to Rocklin.
"Who knows? Maybe I'll be a better center than I am now," Sapolu said. "(But) I like the center I was when I was snapping right-handed."