MADISON (AP) — Baseball commissioner Bud Selig is still reviewing cases of players accused of taking performance-enhancing drugs outlined in the Mitchell Report.

Selig initially hoped to complete his review by spring training.

Yesterday, he said he does not know when he will finish or what punishment he will pursue.

Selig declined to comment on the congressional hearing last week when Roger Clemens denied using performance-enhancing drugs.

"I don't want to respond to what players have or haven't said," Selig said.

The 409-page Mitchell Report was released December 13 Selig said he was examining the cases one-by-one.

"I'm still in that process," Selig said.

Selig's comments came at the same time New York Yankees pitcher Andy Pettitte held a news conference in Tampa, Florida, during which he apologised for taking human growth hormone. Pettitte signed a sworn statement implicating Clemens as an HGH user.

The report by former Senate majority leader George Mitchell linked more than 80 players to drug use. Selig defended baseball's efforts, saying the game had the "toughest drug testing program in American sports."

The commissioner was at the University of Wisconsin to speak with history students.