At the University of Arkansas, Thielemann helped the Razorbacks to a 10–2 record, win a share of the 1975 Southwest Conference championship, beat the Georgia Bulldogs in the 1976 Cotton Bowl Classic 31–10, and finish ranked No. 7 in the final AP poll. He also was on the Super Bowl XXII championship Washington Redskins team in 1987 as a member of the Redskins' famed "Hogs" offensive line.