2007-08: Adam Clendening played for the Toronto Marlboros Midget AAA club, scoring 8 goals and adding 42 assists for 50 points while compiling 116 penalty minutes.
2008-09: Clendening split time between the U.S. NTDP U-17 and U-18 squads. In 39 games for the U-17 team, Clendening scored 1 goal and added 13 assists for 14 points. In 23 games for the U-18 team, Clendening scored 1 goal and added 4 assists for 5 points. Clendening played for the USA’s gold medal squad at the 2009 U-18 World Junior Championship, picking up 2 assists in 7 games.
2009-10: Clendening split time between the U.S. NTDP U-18 national squad and the team that competed in the USHL. In 65 games for the U-18 team, Clendening scored 14 goals and added 35 assists for 49 points to go along with 120 penalty minutes. In 26 games for the USHL squad, Clendening scored 4 goals and added 13 assists for 17 points to go along with 44 penalty minutes. Played for the USA’s gold medal squad at the 2010 U-18 World Junior Championship, scoring 3 goals and adding 7 assists for 10 points in 7 games. He was named to the tournament All-Star Team for his efforts.
2010-11: In his freshman season at Boston University, Clendening played in 39 games for the Terriers. He scored 5 goals and added 21 assists for 26 points to go along with 80 penalty minutes. Clendening was named to Hockey East All-Rookie Team. Clendening was shosen in the second round, 36th overall, of the 2011 NHL Draft by the Chicago Blackhawks.
2011-12: Clendening was the leading scorer among defensemen for Boston University as a sophomore and represented the USA at the 2012 U20 World Junior Championship along with fellow Blackhawks prospect Stephen Johns. In 38 games for the Terriers he scored 4 goals with 29 assists and was plus-11 with 64 penalty minutes. After finishing tied for second in Hockey East the Terriers lost to Maine in the Hockey East tournament semifinals. Boston University received an at-large bid to the NCAA tournament; falling to Minnesota in the West Regional semifinals. In six games at the WJC, Clendening scored 1 goal with 4 assists and had 6 penalty minutes on a USA team that finished seventh in the ten-team tournament. In June 2012 he signed a three-year entry-level contract with the Blackhawks; foregoing his final two years of college hockey.
2012-13: Clending was the top offensive defensemen for Chicago’s AHL affiliate Rockford in his first pro season. He scored 9 goals and was second on the IceHogs with 37 assists; finishing +17 with 67 penalty minutes in 73 games. Rockford finished third in the Midwest Division, two points behind Milwaukee for the final Western Conference playoff spot.
2013-14: Clendening once again led Chicago AHL affiliate Rockford in scoring in his second pro season. Skating in 74 of 76 games for the IceHogs he scored 12 goals with a team-high 47 assists and was plus-5 with 64 penalty minutes. Rockford missed the AHL playoffs; finishing fourth in the Midwest Division. Clendening was named to the AHL first all-star team.
2014-15: Clendening made his NHL debut with the Blackhawks against Calgary on November 20th — skating in four games with Chicago after starting the year with AHL affiliate Rockford. Returned to the IceHogs, he was obtained by the Vancouver Canucks on January 29th in exchange for the rights to Swedish defenseman Gustav Forsling. Clendening played 17 games with the Canucks and appeared in 11 regular season games for Vancouver AHL affiliate Utica. In 21 NHL games between the two teams he scored 1 goal with 3 assists and was +2 with 10 penalty minutes, averaging 16:38 minutes of ice time. Clendening played 49 regular season games in the AHL between Rockord and Utica and scored 2 goals with 16 assists, finishing +1 with 48 penalty minutes. He was a big part of the Comets’ run to the Calder Cup finals, scoring 3 goals with 5 assists and finishing +7 with 26 penalty minutes in 23 AHL playoff games. Clendening was re-signed by Vancouver to a one-year contract as a restricted free agent in July 2015. At the end of the month he was traded to Pittsburgh as part of a multi-player and draft pick trade.
Clendening is an offensive defenseman with good puck-moving ability and a solid shot from the point. While he is known for his offensive and ability to transition the puck up ice, Clendening is solid defensively. He doesn't shy away from the physical side of the game and plays with a good deal of intensity. However, Clendening could stand to utilize his intensity and grit more to the benefit of his team. He also needs to keep his feet moving and improve his overall speed.
Clendening made the Penguins out of training camp in 2015-15 but was a healthy scratch in 16 of the team's first 17 games playing in six straight games in mid-November. After an AHL conditioning assignment at the end of December he was traded by the Penguins to Anaheim along with David Perron in the deal for forward Carl Hagelin on January 16th. Waived 10 days later without ever playing for the Ducks he was claimed by the Oilers. Skating in what is basically a late season audition with Edmonton, Clendening will be a restricted free agent at the end of the season. A skating defenseman with the ability to move the puck and organize the attack from the point, his defensive inconsistency is an issue. He may never reach the potential envisioned when he was a second-round pick in 2011 but he will have an opportunity in an organization looking for defensive help.