He had a dominating performance in the 1983 Fiesta Bowl, posting 16 tackles, one safety and one forced fumble, while earning outstanding defensive player honors in a 32–21 win over the University of Oklahoma.

On October 22, 1994, he was inducted into the Arizona State Hall of Fame, as arguably one of the greatest defensive linemen to wear a Sun Devil uniform.

His most memorable game was against the Washington Redskins on November 10, 1985, when he tallied 11 tackles and sacked quarterback Joe Theismann a franchise record 5 times, tying Bob Lilly’s 19-year-old mark.

Against the New York Giants, he intercepted a Phil Simms pass that was batted down by Ed "Too Tall" Jones and returned it 65 yards for a touchdown, making a critical play in a win that helped clinch the NFC East title.

[3] He had a streak of 224 consecutive games played, before being sidelined on September 21 and eventually being placed on the injured reserve list on December 12, 1997.

[4] Jeffcoat retired after playing 15 seasons, with 102.5 sacks, 745 tackles, 194 quarterback pressures, 2 interceptions, 11 fumble recoveries and 2 touchdowns.

[5] On January 28, 2008, Jeffcoat was hired to join Kevin Sumlin's staff at the University of Houston as the defensive line assistant coach.

[6] Prior to arriving in Houston, Jeffcoat was in private business in the Dallas area for two years.

In January 2013, he joined the University of Colorado Buffaloes as the defensive line coach, following the recently hired MacIntyre.

[7] In November 2018, Jeffcoat was hired by Steve Spurrier as defensive line coach for the Orlando Apollos of the Alliance of American Football.

[9] In June 2019, Jeffcoat was hired by Bob Stoops as defensive line coach for the Dallas Renegades of the new XFL.