MLB free agents 2017-18: White Sox sign C Welington Castillo

The White Sox were supposed to be in a rebuilding mode this offseason, with general manager Rick Hahn saying everyone on the team, including stars Jose Abreu and Avisail Garcia, would be available for the right trade offer.

Instead, the White Sox made a somewhat surprising buy Friday, signing free-agent catcher Welington Castillo.

The White Sox announced they have agreed to terms with the 30-year-old backstop on a two-year, $15 million contract with a club option for a third year.

“I don’t think I would have told you a month ago we were going to wind up signing Welington Castillo to a two-year deal with a club option,” Hahn said Friday (via the Chicago Sun-Times). “But ultimately that opportunity arose and we felt it improved us for the short term and potentially for the long, so we moved quickly on it.”

Castilo, who spent last season with the Orioles, last month declined to accept his player option worth $7 million for 2018 in order to test free agency. The veteran is best known for his defensive skills, throwing out an MLB-high 44 percent of base stealers in 2017. But he had enough pop in his bat to hit a career-high 20 home runs with a .813 OPS.

“[Castillo] has been one of the more productive catchers over the last several seasons, and we believe his presence will have a lasting positive effect on our younger pitchers and catchers as they continue their development at the major-league level,” Hahn said.

Castilo begins the season as the starter, supplanting Omar Narvaez and Kevan Smith, who shared duties behind the plate last year. But waiting in the wings is 2016 first-round pick Zack Collins, scheduled to arrive in the Windy City in 2019.