A hard thrower, Nolan had a promising debut on April 15, 1967, when he struck out the side in the first inning en route to a 7–3 victory over the Houston Astros.

[3] He had fifteen strikeouts in the game but was pulled in the eighth after giving up a three-run home run that tied it to Willie McCovey; the Giants won 4-3.

In 1970 Nolan went 18–7 with 181 strikeouts and a 3.26 ERA, helping the Reds to win the NL pennant and establishing himself as one of the league's great young starting pitchers.

Nolan pitched a remarkable nine innings of shutout ball to earn a victory in the 10-inning Game One of that year's National League Championship Series against Pittsburgh.

Selected for the NL team, Nolan was suffering from neck and shoulder pains, and he was forced to withdraw from the game.

In 1975, he earned the Hutch Award, given annually to an active Major League player who "best exemplifies the fighting spirit and competitive desire of Fred Hutchinson by persevering through adversity."

[3][8] He moved back to Oroville in 2003, where he is involved with several charitable and civic organizations and works with high school pitchers.