After all, both players performed reasonably well in their first full season in the big leagues in 2017.
Team brass, however, saw it differently. The Sox on Friday signed catcher Welington Castillo to a two-year deal worth $15 million.
He isn't coming here to be the backup.
Castillo, 30, will receive $7.25 million in both 2018 and 2019. The Sox hold an $8 million option for 2020 with a $500,000 buyout.
The eight-year veteran is coming off the best season of his career. He hit .282/.323/.490 with 20 home runs and 53 RBIs in 96 games with the Baltimore Orioles in 2017. The 20 homers represent a career high, but Castillo has reached double figures in home runs for four straight seasons, so it's not unreasonable to expect him to hit 15 to 20 homers again next season.
Castillo also has worked with manager Rick Renteria before, having been a member of the Cubs in 2014. The Sox are hoping Castillo will represent a defensive upgrade over the Smith/Narvaez combo, as well. He has a history of blocking and throwing well, and last year, he threw out 49 percent of runners who attempted to steal against him (24 of 49).
His 7.4 fielding runs above average in 2017 represent a significant upgrade over both Smith (-7.7 fielding runs) and Narvaez (-10.7 fielding runs). Castillo was considered a below average framer until last year, so the hope is maybe he has mastered that skill and can steal a few strikes for what is expected to be a younger pitching staff.
Certainly, Castillo should provide a better offensive presence. Smith and Narvaez combined for only six home runs last season, and neither man is considered the long-term solution at the position. Castillo is here to bridge a gap for two years, because the Sox's best catching prospect (Zack Collins) isn't expected until 2019 under even the best-case scenario.
If Collins is ready to be an everyday catcher by the 2020 season, then the Sox can simply buy Castillo out. Or, if Collins does not develop, the club can pick up Castillo's option and still be in reasonable shape at an important defensive position for a year in which many people project the Sox to be ready to contend.