GREEN BAY — The Green Bay Packers have placed Niagara Falls native James Starks on the reserve/physically unable to perform list due to a lingering hamstring injury.

Starks, the University at Buffalo’s all-time leading rusher, is ineligible to practice with for the first six weeks of the regular season. After that, he can practice for three weeks before the team must decide whether to put him on the active roster or season-ending injured reserve.

The Packers picked Starks in the sixth round of the draft and he was expected to compete to be the team’s No. 2 tailback behind starter Ryan Grant. Starks initially hurt his hamstring during offseason practices, then days after telling the Gazette the injury had healed, he aggravated it while trying to complete a conditioning test prior to the start of training camp.

Starks was placed on the training camp PUP list at the time and has not practiced since. Coach Mike McCarthy has expressed frustration to reporters about Starks’ slow recovery. Had Starks been able to practice during training camp, he would not have been allowed to be placed on the regular season PUP list.

Running backs coach Edgar Bennett told the Green Bay Press Gazette that Starks has been keeping up in meetings and that the team would have to “trust some of the things that you saw when he was able to practice, as well as what he shoed coming from college.”

Starks missed his entire senior season at UB after having shoulder surgery last August, meaning that if he doesn’t play for the Packers this season, he will enter next year’s training camp having not engaged in full-contact football for two full years.

In Starks’ absence, undrafted rookie running back Quinn Porter had a strong training camp. But after hurting his knee, Porter was placed on season-ending injured reserve.

The Packers now have three running backs on their roster — Grant, 2007 second-round draft pick Brandon Jackson, and Kregg Lumpkin, who spent last season on the practice squad.

Cornerback Al Harris and safety Atari Bigby were also placed on the PUP list Tuesday as the Packers trimmed their roster to 75 players on the first cut-down day of the NFL season.