Dioner Navarro caught James Shields in 586 innings for the Rays, and he wondered Sunday if the right-hander known for his competitiveness might benefit from moving to a White Sox team that expects a little more to be on the line this season.
Shields went 15-14 with a 4.00 ERA in 44 starts with the Padres, including a 4.28 ERA to start this season as they stumbled to a 23-35 record through Sunday.
After Saturday's trade, he will make his Sox debut Wednesday against the Nationals, joining a team that despite its lengthy slump remains in the thick of a tight American League Central race.