During his Major League Baseball career, he played for the Pittsburgh Pirates, Chicago White Sox, San Diego Padres, and Washington Nationals.

[1] Mackowiak continued his baseball career by playing for South Suburban Junior College in Illinois.

In 2001, Mackowiak was promoted to Triple-A, playing for the Nashville Sounds where he improved his game and excelled on the fields.

Mackowiak's first Major League home run came off of Florida's Braden Looper at PNC Park on May 30.

2003 saw Mackowiak's second Opening Day start for the Pirates organization, and continuing his jack-of-all-trades status at the club, appeared at five different positions in his first 10 games (RF, CF, LF, 2B & 3B).

[3] He played as number 10, continued his utility roles at all three outfield positions, third base, and designated hitter.

At the end of July, he was traded to the San Diego Padres for minor league pitching prospect Jon Link.

[2] Mackowiak became a free agent at the end of the season and agreed to a minor league contract with the New York Mets on January 23, 2009.

On June 6, 2009, Rob was signed by the Cleveland Indians and reported to their AAA team, the Columbus Clippers.

In 2010, the Windy City ThunderBolts announced that Rob Mackowiak was hired as the team's hitting coach.