In response to Dick Allen, I seem to remember the Sox wanting Shields quickly to improve their rotation. Wasn’t Erik Johnson in the rotation at the time? Also, the Padres initially requested Tim Anderson but settled for Tatis Jr. I guess the trade would have been disastrous whichever way they went.
https://www.sbnation.com/2016/6/4/11858938/james-shields-trade-white-sox-padres
“The Padres receive right-handed pitcher Erik Johnson and infielder Fernando Tatis Jr. in exchange for Shields and cash in return. Chicago refused to part with shortstop Tim Anderson, their top prospect, per Jon Heyman.
The White Sox entered Saturday at 29-26, 1½ games out of first place in the American League Central, though they are just 2-8 in their last 10 games.”