|Williams quickly proved too good for his Minor League assignment (Esquire)|
By the time Williams arrived to the Major Leagues in 1939, he was already a finished product. Having destroyed American Association pitching the previous year, he promptly set fire to the Majors with one of the greatest rookie seasons ever. In addition to leading the loop in RBIs with 145, the 20-year-old Williams batted .327/.436/.609 with 31 home runs en route to a fourth-place MVP finish.
Williams had been ready for some time, however, and should have debuted in 1938. He didn't make the team out of Spring Training, unable to crack Boston's veteran outfield of Joe Vosmik, Ben Chapman, and Doc Cramer, all of whom would bat .300 that year. None of them could hit for much power, however, slugging just 15 homers between them, with Cramer hitting none. Williams had already showed his natural power stroke the year before with San Diego, swatting 23 home runs as a skinny 18-year-old in the Pacific Coast League, and would have added thump to a lineup that was starved for power beyond Jimmie Foxx.
Furthermore, the men Williams might have replaced in the outfield weren't fan favorites or established stars with the team, as none had spent more than two years with the Red Sox. While veterans are always given a chance to keep their jobs and rookies tend to be treated with kid gloves, nobody's feathers would have been ruffled had Joe Cronin benched one of them in favor of Williams.
While it's understandable that the Red Sox wanted Williams to get regular at-bats rather than sit on the bench behind the aforementioned trio, they should have called him up later in the season. By August they were out of the pennant race and it was clear that Williams had nothing more to learn with Minneapolis, where he won the league's Triple Crown with 43 homers, 142 RBIs and a .366 average. Chapman was months away from being traded and clearly wasn't in the club's long-term plans, so why not give the Kid a shot? With Foxx having a season for the ages, setting a then-franchise record with 50 homers, Boston already had the perfect lineup protection for Williams, who could have cut his teeth on a steady diet of fastballs hitting in front of Double X.
The Red Sox had other motivations for keeping Williams down on the farm longer than necessary, however, namely his maturity. He had rubbed many teammates and coaches the wrong way with his big mouth, and it was felt that he needed time in the Minors not just for seasoning, but to grow up. If Williams had been less of an annoyance, the Sox might have been willing to give him a chance. Instead, they may have hoped to humble him with the demotion.
It all worked out in the long run, however; as fate would have it, Rogers Hornsby was one of the Millers coaches that year. Williams learned a lot from the best right-handed hitter of all-time, namely "get a good pitch to hit." The Splendid Splinter took that to heart, walking more than 2,000 times in his career, but it's possible that he wouldn't have been so patient had he never come under Hornsby's tutelage.