STANFORD, CA – Chester McGlockton, a four-time Pro Bowl defensive lineman who emerged as a talented assistant coach and mentor at Stanford, died Wednesday. He was 42.

McGlockton also spent time helping the San Francisco 49ers and former Cardinal coach Jim Harbaugh – his former racquetball partner – during training camp this summer as part of the Bill Walsh Minority Coaching Fellowship.

Harbaugh expressed sadness and shock upon hearing of McGlockton’s death. Stanford said the school’s defensive assistant died overnight.

A native of Whiteville, N.C., McGlockton starred at Clemson before being selected 16th overall by the Los Angeles Raiders in 1992. He played 12 seasons in the NFL.  He made all four of his Pro Bowl appearances while with the Raiders from 1994-1997.

McGlockton’s best season came in 1994, when he had a career-high 9 1/2 sacks with three forced fumbles and 48 tackles.