Paul Brown, the head coach and general manager of the NFL's Cleveland Browns, appointed Temerario the team's ends coach and chief scout in April 1950. He replaced Dick Gallagher, who had left to become the head football coach at Santa Clara University. Led by quarterback Otto Graham and ends Dante Lavelli and Mac Speedie, the Browns finished with a 10–2 regular-season record and won the NFL championship in Temerario's first year. He continued in Cleveland through the 1951 season, when the Browns again reached the NFL championship but lost to the Los Angeles Rams.