The White Sox dealt infielder Boze Berger to Boston for third baseman Eric McNair. The swap was a huge win for the White Sox, as in 1939 McNair slashed .324/.375/.426, logged 2.2 WAR and finished 29th in MVP voting.
Berger is notable in that he was just coming off the (at the time) worst season ever for a White Sox hitter (-2.0 WAR, tied with the 1934 effort of second baseman Bob Boken) — a season that remains tied for third-worst ever among White Sox hitters and tied for 10th-worst overall in South Side history.
Berger ended his career with -2.2 WAR, and as you might imagine did as little for the Red Sox as he did the White, playing in just 20 games in 1939 and never appearing in the majors again.
Mary Shane was hired by the White Sox as one of the first women play-by-play announcers in baseball history, and arguably the first hired as a regular broadcaster. However, Shane ended up joining Lorn Brown, Harry Caray and Jimmy Piersall in the booth for just around 20 games in 1977, mostly at home, and was pulled out of any regular rotation before the season ended.
Closer Bobby Jenks, battling injury for much of the season, bolted the White Sox for a two-year, $12 million deal with Red Sox. Jenks suffered his worst MLB campaign in 2010, with 27 saves in 55 games and an 4.44 ERA — the first time his ERA had ever been worse than league average (97 ERA+).
Things got much worse in Boston, as he would pitch just 19 more MLB games and record zero saves for the Red Sox. He didn’t pitch after July 7 and underwent back surgery five months later — surgery that turned out to be concurrent with another patient. Jenks developed complications and needed a spinal tap to drain excess fluid, a life-threatening situation. The closer, unable to play again, won a $5.1 million lawsuit against the hospital and surgeon.
In 2022, Jenks was named the Pioneer League Manager of the Year for his success with the Grand Junction Rockies.