2008-09: Klinkhammer skated in 76 games for AHL Rockford in his second pro season – scoring 15 goals with 18 assists and was plus-14 with 32 penalty minutes. In four playoff games he had 1 assist. The Chicago Blackhawks signed Klinkhammer to a two-year entry-level contract in March 2009.
2009-10: Klinkhammer returned to Rockford following Blackhawks camp and skated in 72 games for the Ice Hogs. Playing primarily a defensive, lower line role for Rockford he scored 10 goals with 13 assists and was minus-five with 38 penalty minutes. In four playoff games with Rockford he had 1 goal and 1 assist and was minus-one with 7 penalty minutes. Klinkhammer was re-called briefly by Chicago at the beginning of the year but did not appear in any games.
2010-11: Klinkhammer made the first NHL appearance of his career in Chicago's December 8th game against Dallas — spending the bulk of his fourth pro season with the Blackhawk's AHL affiliate Rockford. He was plus-one in 18 shifts (11:36 of ice-time) in his only NHL game. Klinkhammer was Rockford's third-leading scorer, finishing with 17 goals and 29 assists in 76 games and was a team-best plus-14 with 63 penalty minutes. Rockford missed the AHL playoffs. The Blackhawks re-signed Klinkhammer to a one-year contract in July 2011.
2011-12: Klinkhammer was traded from Chicago to Ottawa in December 2012 and appeared in 15 NHL games with Ottawa after being re-called in March. He was with the Senators during the playoffs but did not appear in any games. He had 2 assists and was an even plus/minus with 2 penalty minutes; averaging 11:26 minutes of ice time for the Senators. Prior to the trade he spent the year in the AHL with first Rockford and then Binghamton. In 53 AHL games between the two clubs he scored 14 goals with 27 assists and was minus-nine with 36 penalty minutes. He signed a one-year free agent contract with Phoenix in July, 2012.