Greg Ostertag did not participate in the scrimmage, and the possibility is increasing the 7-foot-2 center could open the season on the injured list.
   
The seven-year veteran has had some cramping near the 4-inch scar he earned when he donated a kidney to his sister this summer. Ostertag will undergo an abdominal scan on Monday to make certain there are no internal problems, but even if everything is OK, the center's conditioning remains a problem.