Amateur Loewen first gained attention of the
Western Hockey League (WHL)'s
Spokane Chiefs at 14 years old, and they placed him on their protected list. He made his WHL debut when he was 16 in the
1985–86 season, but his parents convinced him to finish his education before playing hockey full time. He appeared in eight games with the Chiefs, scoring two
goals, one
assist and three
points. His first full season with the Chiefs in
1986–87 he played in 68 games, scoring 15 goals and 40 points. He was supposed to serve an automatic one-game suspension in December 1986 after receiving three
game misconduct penalties during the season. However, Spokane played Loewen in the game he was supposed to be suspended for, automatically adding two games to the suspension. Loewen sat out the three games in January 1987 instead. His play during the season as a 17-year-old saw the newspapers referring to him as the "heart and soul" of the Chiefs' team. The Chiefs made the 1987 WHL playoffs but were swept in the first round by the
Portland Winterhawks in five games. Loewen added one goal in the five games. He improved his scoring, marking 30 goals and 74 points in 72 games. The Chiefs made the 1988 WHL playoffs and advanced to the semi-finals, eventually losing to the
Kamloops Blazers. In 15 playoff games, Loewen added seven goals and 12 points. He returned for a third season with Spokane in
1988–89, retaining the captaincy. In a game versus the Kamloops Blazers on November 11, 1988, Loewen
cross-checked Ed Bertuzzi from behind, igniting a brawl that led to the referees ending the game prematurely as they and security attempted to get the two teams under control. For his role in the altercation, Loewen was suspended indefinitely until the league sorted the matter out, eventually being ordered to sit out three games. He was selected again to represent the Chiefs at the 1989 WHL All-Star Game. He finished the season with 31 goals and 58 points in 60 games. After signing his contract, he was to play with Buffalo's
American Hockey League (AHL) affiliate, the
Rochester Americans, but Loewen broke his
collarbone in his final junior game and missed the rest of the season. He signed a new contract in the 1989 offseason and was assigned to Rochester to start the
1989–90 season. He played in his first professional game against the
Newmarket Saints on October 8, 1989. He appeared in 50 games for the Americans, scoring seven goals and 18 points. Both he and Guay were returned to Rochester on March 19. However, he was immediately recalled on March 21, and played in three more games for Buffalo that season, going scoreless. He played in five playoff games, scoring one goal. Loewen began the
1990–91 season with the Sabres playing on the fourth line alongside
Mike Hartman and
Rob Ray. As the Sabres struggled to open the season, he moved up the lineup, playing on a with
Dale Hawerchuk and
Rick Vaive. He played in five games, going scoreless, before being assigned to the AHL on October 24, 1990. He spent the majority of the season with Rochester, playing 71 games and registering 13 goals and 28 points. The Americans made the
1991 Calder Cup playoffs and Loewen appeared in 15 playoff games, adding one goal and six points. The
1991–92 season was spent mostly in the AHL with Rochester. There, Loewen played in 73 games, scoring 11 goals and 31 points. He made his NHL season debut that night against the
Chicago Blackhawks. He played one more game for the Sabres, going scoreless, before being sent back to the AHL on March 11. The Americans made the
1992 Calder Cup playoffs, with Loewen playing in four games, registering one assist. However, he partially tore a
ligament in his right knee on April 10 in Game 2 of their first round series against the
Hershey Bears and was out for three weeks. He returned to play on May 12 in the semi-final against the
Adirondack Red Wings. He played one more game before missing the final game due to
back spasms as the Americans were eliminated by the Red Wings.
Ottawa Senators In the 1992 offseason, the NHL expanded by two teams, the
Ottawa Senators and the
Tampa Bay Lightning. Loewen was among the players left unprotected by the Sabres in the
1992 NHL expansion draft. He was selected by Ottawa and signed a two-year, two-way contract with the team. Though he was invited to their training camp, he was not expected to make the team. However, after surprising the team with his play, he made the Senators and was a member of Ottawa's opening night roster on October 8, 1992. Loewen's hard work and intensity made him a fan favourite in Ottawa, becoming the team's "heart and soul" during its first season. He scored his first NHL goal on October 27 in a 7–2 loss to the
Pittsburgh Penguins. He played in 79 games with the Senators during their inaugural season in
1992–93 recording four goals and nine points. On October 18, 1993, Loewen signed a new, two-year contract with Ottawa. However, the injuries started to pile up beginning at the start of December. First he had a bruised foot, but still managed to get into games. Then, he suffered a bruised thigh/
charley horse that kept him out for four games. Then, at the end of December, he suffered his worst injury,
straining his knee ligaments, sidelining him until February 1994. He played in 44 games for the Senators that season, registering only three assists. He did not sign with another team in that period and the Senators bought out his remaining contract. On August 5, it was announced that he had signed a one-year contract with the
Las Vegas Thunder of the
International Hockey League (IHL). In the
1994–95 season, Loewen appeared in 64 games, scoring 9 goals and 30 points. The Thunder made the 1995 Turner Cup playoffs, in which he played seven games, scoring one goal and two points. and put up a career-high 14 goals and 37 points in 72 games. The following season he tied his career-high in goals with 14, but only got 33 points in 76 games. In his third season he scored four goals and ten points in 42 games with Las Vegas He finished the season with the Grizzlies, playing in 34 games, scoring one goal and eight points. He spent the next season splitting time between the
Idaho Steelheads of the
West Coast Hockey League (WCHL) and the
Nottingham Panthers of the British
Ice Hockey Superleague (BISL). He appeared in three games with Idaho, marking one goal and three points. and appeared in Nottingham's win over the
Manchester Storm in the Benson & Hedges Cup. He played 28 games in the BISL, registering three goals and six points. He spent the 1999–00 season in the WCHL with Idaho, playing in 62 games, scoring nine goals and 25 points. However, the retirement was short-lived and Loewen returned in December for the 2000–01 season, scoring two goals and six points in 39 games. ==International play==