SALT LAKE CITY -- With two preseason games under his belt, Jazz coach Jerry Sloan has already identified a few bright spots - and an area of concern.

Sloan is pleased with the progress of his young players, particularly Andrei Kirilenko and DeShawn Stevenson, but he is disappointed with production of his centers.

Greg Ostertag and John Amaechi are a combined 5-for-24 shooting in the preseason and Sloan believes they are letting a good opportunity slip away.

"When we get inside," Sloan said, "our big guys have got to be able to execute, they"ve got to be able to rebound, they"ve got to be able to block some shots, they"ve got to be a force in there.

"And our big guys are not in real good shape."