2008-09: Tanev skated in 50 games for the Markham Waxers in his second season in the Ontario Junior Hockey League. He scored 4 goals with 37 assists and had 33 PMs. Tanev committed to playing college hockey at the Rochester Institute of Technology.
2009-10: Tanev was named the Atlantic Hockey League Rookie of the Year and selected to the league's All-Tournament team as a freshman at RIT. He posted 10 goals and 18 assists and was +34 with 4 PMs in 41 games. Tanev played a key role as the Tigers won the Atlantic Hockey regular season and playoff titles and made an unlikely run to the NCAA Frozen Four. He signed an entry-level, three-year contract with the Vancouver Canucks in June 2011, foregoing his final three years of college hockey.
2010-11: Tanev made his NHL debut with Vancouver in January 2011 and skated in 29 games for the Canucks. He was also with Vancouver during the team's run to the Stanley Cup Finals, joining the team after the AHL playoffs and seeing limited ice time in five games. He had 1 assist and was an even plus/minus while averaging just under 14 minutes of ice time during the regular season. He had no points nor penalties and was an even plus/minus in the playoffs. In 39 AHL regular season games with the Moose he had 1 goal with 8 assists and was +5 with 16 PMs. He skated in all 14 playoff games for Manitoba and was +7 with 1 goal and 2 assists.
2011-12: Tanev once again split the season between the Canucks and their AHL affiliate in his second pro season. After spending the first three games with the Canucks he was demoted to Vancouver's new affiliate in Chicago. He returned for one game in January before re-joining the Canucks for good in February. Tanev had 2 assists and was plus-10 with 2 penalty minutes in 25 regular season games; averaging just under 17 minutes of ice time per game. He played in all five games during the Canucks first round series with Stanley Cup champion Los Angeles, averaging 15 minutes of ice time, and was an even plus/minus with no points nor penalty minutes. Tanev had 14 assists and was plus-12 with 6 penalty minutes in 34 AHL games with the Chicago Wolves.