After losing his first two starts against the New York Yankees[4] and Detroit Tigers,[5] he got his first major league win out of the bullpen against the Cleveland Indians.

He was traded after the 1973 season with Mike Garman and Lynn McGlothen to the St. Louis Cardinals for Reggie Cleveland, Terry Hughes and Diego Seguí.

With the new designated hitter rule to go into effect the following season, Curtis became the last pitcher to ever bat at Fenway Park on September 28, 1972, in the bottom of the seventh inning in a 3-1 Red Sox win against the Kansas City Royals.

[8] The Cards were battling the Pittsburgh Pirates for first place in the National League East all season when the Bucs came to Busch Stadium for a three-game set September 23–25, 1974.

After the 1976 season, he was traded to the San Francisco Giants with Willie Crawford and Vic Harris for Mike Caldwell, John D'Acquisto and Dave Rader.

[11] After a nearly twenty-year absence from the game, he returned to coach the Long Beach Breakers during the two-year run of the independent Western Baseball League (2001 and 2002).