Cross played his first two years of high school hockey at his public Simsbury High School in Simsbury, Connecticut; garnering Connecticut player of the year honors his sophomore season. Cross was playing high school hockey when he was first originally drafted by the major junior club Moncton Wildcats of the Quebec Major Junior Hockey League, 252nd overall in the 2006 Entry Draft. With little intention to pursue a major junior career in Canada, Cross continued his development through prep, and featured with the Ohio Junior Blue Jackets of the United States Hockey League to end the 2007–08 season. He committed to a collegiate career with Boston College of the Hockey East. At the conclusion of his senior season culminating in captaining the Eagles to his second NCAA Championship, Cross was signed by the Bruins to a two-year entry-level contract on April 11, 2012. Cross immediately made his professional debut at the tail end of the 2011–12 season, with Boston's AHL affiliate, the Providence Bruins. After two seasons with the P-Bruins, having solidified a position on the blueline, Cross was given a one-year extension with the Bruins on July 18, 2014. In the 2014–15 season, in his third full season in the AHL, Cross established career highs offensively with 4 goals and 18 assists for 22 points in 54 games. Cross was announced as the Providence Bruins captain to begin the 2015–16 season. He featured in the opening two games with Providence before he received his first NHL recall by Boston on October 14, 2015. He made his long-awaited NHL debut with the Bruins, alongside teammate Tyler Randell in a 6–2 victory over the Colorado Avalanche on October 15, 2015. He later registered his first point, an assist, in his second career game against the Arizona Coyotes on October 17, 2015. On June 14, 2017, the Bruins re-signed Cross to a one-year, two-way contract worth $650,000. After six seasons within the Bruins organization, Cross left as a free agent to sign a one-year, two-way contract for $650k with $450k guaranteed with the Columbus Blue Jackets on July 1, 2018. In the 2018–19 season, Cross appeared in 73 regular season games with the Cleveland Monsters of the AHL, affiliate to the Blue Jackets, producing 34 points. Cross left the Blue Jackets at the conclusion of his contract to sign a two-year, two-way contract as a free agent with the Florida Panthers on July 1, 2019.
