Also a potentially really important hole to make.
The White Sox record in 1 run games this year was really, really good. 27-16. Houston, Seattle, San Diego were a tiny bit better, Cleveland was 28-17, so effectively tied for 4th best record in 1 run games. This was the big factor that allowed them to be .500 despite having a negative run differential.
At least in part, this is because the White Sox's back of the bullpen was quite reliable for much of the year. Their bullpen had crappy depth, so if a team got into the White Sox's middle relievers, they gave up a 5 spot or something like that and it didn't end as a close game. But, if they got to the 7th or 8th inning in a tight game and handed it to their top 2 or 3 relievers, they didn't give the game up very often.
Take that away, have to rely on the nonexistant bullpen depth even more, could have an outsized impact on the results.