Daniel Lee Dierdorf (born June 29, 1949) is a former American football offensive lineman and current sportscaster. A native of Canton, Ohio, Dierdorf played college football for the University of Michigan from 1968 to 1970 and was selected as a consensus first-team All-American in 1970 and a first-team All-Big Ten Conference player in 1969 and 1970. He was inducted into the University of Michigan Athletic Hall of Honor in 1996 and the College Football Hall of Fame in 2000. Dierdorf played professional football in National Football League (NFL) with the St. Louis Cardinals for 13 seasons from 1971 to 1983.

From 1974 to 1976, Dierdorf started every game at right tackle for the Cardinals during a three-year span in which the team compiled records of 10-4, 11-3, and 10-4 under head coach Don Coryell. In 1977, Dierdorf sustained a broken jaw and missed two games to injury as the Cardinals fell to 7-7. In 1978, Dierdorf started all 16 games at right tackle for the Cardinals.  During his peak years from 1974 to 1978, Dierdorf was regarded as one of the best offensive lineman in the NFL. He was selected by the National Football League Players Association as the Offensive Lineman of the Year for three consecutive years from 1976 to 1978. The Cardinals' offensive line, led by Dierdorf, Conrad Dobler, and Tom Banks, led the NFL with the fewest sacks allowed for three years (and the National Football Conference for five years) in the mid-1970s. In 1975, the group set an NFL record, allowing only eight sacks in 14 games.  Dierdorf did not allow a sack during the entire 1976 and 1977 seasons. His streak ended in the first game of the 1978 season when Chicago Bears defensive end Tommy Hart tallied two sacks against Dierdorf. Dierdorf had not given up a sack since the 1975 NFC Divisional playoff game when Jack Youngblood sacked Jim Hart.  Dierdorf was selected to play in the Pro Bowl for five consecutive years from 1974 to 1978. Dierdorf also received first-team All-NFL honors as follows: in 1975 from the Pro Football Writers Association (PFWA); in 1976 from the Associated Press (AP), PFWA, Newspaper Enterprise Association (NEA), and Pro Football Weekly (PFW); in 1977 from AP, PFWA, NEA, and PFW; and in 1978 from AP, PFWA, NEA, PFW. He was named as the NFC choice for the NFLPA/Coca-Cola Offensive Lineman of the Year Award three straight years (1976-78) and was the Seagram's Seven Crowns of Sports Offensive Lineman of the Year in 1975. He also won the Forrest Gregg Award for NFL Offensive Lineman of the Year in 1975. Answer this question using a quote from the following article:

what did he do after the three years?
Dierdorf did not allow a sack during the entire 1976 and 1977 seasons.