2019: The defender played and started in 24 matches for NYCFC. His strength in the defensive line helped the club to reach the top spot in the Eastern Conference table and also saw him become a regular name on Peru's national team squad.
2018: Callens played and started 31 matches for NYCFC, racking up 2,750 minutes of game action and scoring one goal along the way, helping lead New York City at the back to a third straight MLS Cup Playoffs appearance. The Peruvian international signed to a long term contract at the end of the season.
2017: NYCFC’s 2017 Defensive Player of the Year arrived this past offseason from Spanish club CD Numancia and locked down a spot in Patrick Vieira’s XI in short order. Callens played every single minute of the 2017 regular season, anchoring the back line to the league’s fourth-best goal differential and the Club’s best-ever finish.
2015: Callens signed with CD Numancia for 18 months where he played 40 times.
2011-2014: Callens signed with Real Sociedad from Spain, making 86 Division B league appearances before making his debut with the first team in December 2014.
Youth: Callens emerged through the youth ranks at six-time Peruvian champions Sport Boys in his homeland.