He played in Major League Baseball (MLB) for the Baltimore Orioles, Toronto Blue Jays, Philadelphia Phillies, and Arizona Diamondbacks.

After spending the next two seasons in the minor leagues as a position player, Loewen converted back to a pitcher, and was called up to the Phillies in August 2015.

While still in high school, he pitched a no-hitter against the Dominican Summer League Pirates for the Canadian national baseball team.

[2] The Baltimore Orioles selected Loewen in the first round, with the fourth overall pick, of the 2002 Major League Baseball draft.

Loewen went on to play one season with Chipola College, but signed a Major League Baseball contract with Baltimore worth $4.02 million shortly thereafter.

[citation needed] Loewen garnered international attention on March 8, 2006, when he started for Canada against the United States team in the first round of the 2006 World Baseball Classic.

This made Loewen the first pitcher in Major League Baseball history to face Cy Young winners in his first four starts.

[8] Although he was subsequently converted into a relief pitcher when he returned in July, he experienced a sharp pain in his surgically repaired elbow.

Due to the nature of his injury and his inability to remain as a pitcher, Loewen had the Orioles' support when he made the decision to transition to a position player.

The Orioles had hoped to develop Loewen to play at first base but were also actively in the market to sign free agent first basemen.

[13] During 2011 with Triple-A Las Vegas, Loewen batted .306 with 17 home runs and 85 RBI in 134 games, which also saw him play all three outfield positions as well as first base.

[17] In a game against his former team, the Baltimore Orioles, on September 11, Loewen hit his first career home run, a solo shot over the centre field wall off starter Tommy Hunter.

[14] The Toronto Blue Jays announced on January 12, 2013, that Loewen had been signed to a minor league contract with an invitation to spring training.

[30] In 50 appearances out of the bullpen split between the Double–A Frisco RoughRiders and Triple–A Round Rock Express, he accumulated a 6–1 record and 3.81 ERA with 67 strikeouts across 52 innings pitched.