2006-07: In his first season with the Smiths Falls Bears (CJHL), Mark Borowiecki tallied three goals and 28 points through 53 games. He also racked up a career-high 85 penalty minutes.
2007-08: The Smiths Falls Bears (CJHL) defenseman netted a pair of goals and 26 points through 46 games in his second season with the club. He was voted this years CJHL Best Defenseman and was nominated to the CJHL All-Star Team.
2008-09: Borowiecki tallied a goal and two points in 33 games with Clarkson University (ECAC), his first season as a Golden Knight.
2009-10: Borowiecki skated in 35 games with Clarkson University as a sophomore. He tallied 8 goals and 11 assists and was -2 with 24 PMs on a Golden Knights that finished last in ECAC Hockey and won just nine games.
2010-11: Borowiecki joined AHL Binghamton after signing a two-year, entry-level contract with Ottawa in March 2011 following his junior year at Clarkson. He skated in nine regular season games for Binghamton and was scoreless and -2 with 6 PMs. Borowiecki played in 21 of 23 playoff games as Binghamton captured the AHL championship and was +5 with 2 assists and 8 PMs. In his final college season with the Golden Knights, Borowiecki was a team captain and skated in 31 games; scoring 3 goals, all on the power play. He had 9 assists and 67 PMs and was -8 on a Clarkson team that tied for seventh in ECAC Hockey.
2011-12: Borowiecki made his NHL debut — appearing in two January games with the Ottawa Senators — and provided both physical play and offensive playmaking for AHL Binghamton in his first full pro season. He had no points and was minus-one with 2 penalty minutes, averaging 12:29 minutes of ice time, in his brief stint with Ottawa. Borowiecki scored 5 goals with 17 assists and was an even plus/minus in 73 games for Binghamton. He was third on the team with 127 penalty minutes and was named to the AHL All-Star game. Binghamton missed the playoffs; finishing fifth in the East Division.
2012-13: Borowiecki appeared in six NHL games with the Senators and led Ottawa's AHL affiliate in Binghamton in penalty minutes in his second pro season. He had no points and was +1 with 18 penalty minutes; averaging 13 minutes of ice time per game with Ottawa. In 53 AHL games he scored 4 goals with 10 assists and was +21 with 157 penalty minutes. Binghamton finished second in the East Division and had the AHL's fourth-best record before being swept by Wilkes-Barre/Scranton in a first round series. Borowiecki scored 1 goal and was an even plus/minus with 4 penalty minutes in three playoff games. He was re-signed by Ottawa to a two-year contract as a restricted free agent in July of 2013.