As a 20-year old, Rozema had an excellent rookie season for the Detroit Tigers in 1977, when he won 15 games and finished in the top five in the league in ERA. He later served as a spot starter and reliever on the 1984 World Series champions. He was a native of Grand Rapids who was popular with fans in his home state, though he never lived up to the promise of his first season.
The big righty tossed 16 complete games as a rookie, giving Detroit the top rookie pitcher in both '76 (Mark Fidrych) and '77. In that rookie season, Rozema finished 8th in Cy Young Award voting. He pitched just as well in 1978 but got poor run support and his record fell to 9-12. He still completed 11 games and tossed two shutouts in his sophomore season. The following year he suffered the first of many nagging arm troubles and pitched in only 16 games. It's been speculated that his high innings pitched totals at the ages of 20 and 21 (427+ in those two years) contributed to the burnout in his arm. Manager Ralph Houk was known for using his pitchers up, and Rozema was likely one of the casualties of that practice.
"Rosy" was a left-hander in a right-hander's body - he was impetuous, flaky, and wild at times. He once spent a stint on the disabled list after sitting down on a chair with a glass bottle of cough medicine in his back pocket. He famously injured his knee in 1982 when he tried to deliver a flying karate kick during a brawl between the Tigers and Minnesota Twins. He missed most of the season with that injury after having one of the best starts of his career. He kept the clubhouse loose in Detroit and became best friends with teammate Kirk Gibson, the two of them even married sisters.
On the mound Rozema was known best for his excellent changeup. He utilized great arm action to keep batters off balance with the pitch, and even though his fastball rarely hit 90 MPH, the effectiveness of his changeup was his best weapon. He exhibited great control, walking about two batters per nine innings over the course of his 10-year career.
Rozema fell out favor a bit with manager Sparky Anderson because of his antics, and he found himself in the bullpen much of the time after the grey-haired skipper arrived midway through the '79 season. The arrival of more talented pitchers Jack Morris and Dan Petry also took some of the shine off Rozema's stature.
He left the Tigers as a free agent after the '84 season, signing with the Texas Rangers. He finished his career in 1986 with 60 victories, 36 complete games, and a 3.47 ERA in 248 games.