Over those six appearances Caldwell posted a record of 1-0 without giving up a single earned run, throwing 6.2 innings of scoreless ball as a 22-year-old.
He would go on to pitch another two seasons with the Padres before moving on to the San Francisco Giants in 1974, having his first successful year with a record of 14-5 and a 2.95 ERA over 31 appearances, 27 of them starts.
He’d struggle over the next two years before starting the 1977 season with the Cincinnati Reds, appearing in 14 games as a reliever before being traded to the Milwaukee Brewers for two Minor Leaguers on June 15th.
In Milwaukee he would find his groove, going on to pitch seven-plus years for the “Brew Crew”, posting double-digit win totals six times including his magnificent 1978 campaign, which saw him go 22-9 with a 2.36 ERA over 34 starts, completing 23 of them and tossing six shutouts.
If it were not for a man named Ron Guidry that season, Caldwell would have taken home the American League Cy Young Award, finishing second while also finishing twelfth in the MVP race.
By the time he retired after the 1984 season, Caldwell ended up with a career 137-130 record along with a 3.81 ERA in 475 appearances, 307 of them starts, with 23 shutouts, 18 saves and a brilliant 1982 World Series performance in a losing cause when he went 2-0 over three games, posting a 2.04 ERA including a shutout against the St. Louis Cardinals.