The Chicago White Sox were not expected to be competing atop the AL Central this season.

A surprise year has put Chicago in contention for an AL Central crown, and the front office knows it. That was shown Saturday night when it acquired a much-needed arm to add to the starting rotation.

Luis Castillo is headed to the White Sox

According to MLB insider Jeff Passan, the White Sox have acquired Seattle Mariners right-hander Luis Castillo.

In return, Seattle will receive relief pitcher Seranthony Domínguez, outfielder Nolan Jones and catching prospect Boston Smith.

A change of scenery for Luis Castillo could be a great thing

Castillo has struggled in Seattle this season, pitching to a 5.06 ERA across 20 appearances and 99 2/3 innings. Castillo also grew frustrated with his role earlier this season, when he was used out of the bullpen as a piggyback option behind Mariners starter Bryce Miller.

A move from a slumping Seattle team to a competitive and hungry Chicago team could be exactly what the 10-year veteran needs to rejuvenate his career.

Seattle is getting an intriguing return package

Seattle is also coming out on the positive end of the trade in acquiring Dominguez (4.10 ERA, 12 saves) and Jones (career .247 hitter, 30 home runs).

It does beg the question, though, as to whether Jones could be a potential replacement for current Seattle outfielder Randy Arozarena, who has been a name that has been mentioned in trade deadline rumors.

Whatever the roles of the swapped players turn out to be, it feels as if both teams came out on the winning end and are positioned to benefit both in the present and in the future.