Rivera attended Elmont Memorial High School, where he played at guard, defensive end and linebacker.

As a sophomore, he became a starter at right tackle, but was lost for the season with a shoulder injury he suffered in the ninth game against the University of Illinois.

[1] As a junior, he was moved to right guard, contributing to the team leading the nation in scoring (47.8 points-per-game) and total offense (520.2 yards-per-game).

Rivera returned to Green Bay and saw action in 14 regular season games, primarily on special teams as a member of the field goal and extra point units and on kickoffs.

In 1998, Rivera started 15 of 16 regular season games at the left guard spot after winning the job in training camp over another ex-Claymore, Joe Andruzzi.

In 2002, Rivera raised his game to a higher level in his fifth season as a starter with a performance that earned him his first career Pro Bowl selection.

He was named as a starter on the NFC Pro Bowl squad after serving as a backup for his initial appearance in the NFL's annual all-star game in 2002.

He injured his back during an offseason workout while running on a treadmill and underwent microdiscectomy surgery to repair a herniated disc.

[7] He recovered in time for training camp and the regular season, but suffered a sprained neck injury against the Washington Redskins in week 15 and would miss the final two games.