When Castillo signed with Xolos, his career had stagnated. Once a promising prospect at Club America, he struggled for the club and had loan spells with Tigres, San Luis and Puebla, but none were dying to sign him long-term. Then Xolos took him on loan in 2012 and he shone, pushing the club to buy him outright and spurring a tremendous stint with the club.
In two and a half years at Xolos, Castillo helped the club win the league, make the Copa Libertadores quarterfinals and establish the Tijuana in the U.S. While Castillo's play wasn't always great, he was a fixture, filling in at right back at times as the club continued their amazing ascent from non-existent, to the second division, to the first division -- when Castillo joined them --, to Mexican champions.
Atlas finished 15th in the Apertura and 12th in the Clausuea so they are definitely a club in need of help. They head into next season in the relegation battle so Castillo will be thrown right into high stakes soccer. Atlas used several players at left back last season, but none of them played particularly well so Castillo should be able to come in and win the job straight away.
Castillo was still a fixture for Xolos in the Clausura, but the 27-year-old was no longer needed at the Estadio Caliente. The rise of Greg Garza, also an American, gave Tijuana a younger, cheaper option at left back. Cesar Farias moved Garza around last season, using him at right back and even center back, but he spoke highly of the 22-year-old and it appears as if he is being given a chance to lock down left back now.
At 27 years old, Castillo still has time left in his career and Jurgen Klinsmann has shown a preference for attack-minded left backs so he could very well play his way back into the U.S. picture with some strong play for Atlas. And if he doesn't, maybe Garza will.