Roland entered the majors in 1962 with the Minnesota Twins, playing for them six years (1962–64, 1966–68), before joining the Oakland Athletics (1969–72), New York Yankees (1972) and Texas Rangers (1972). A starter converted to long relief duties, he possessed a hard fastball and a dominant curve, but his delivery was bothered by control problems for most of his career. His most productive season came in 1969, when he posted career-numbers in wins (five), earned run average (2.19), games (39) and innings pitched (86+1⁄3). After that his career declined due to a nerve problem in his throwing arm, pitching a combined 23 innings for Oakland, New York and Texas in 1972, his last major league season.
In a 10-year career, Roland went 19–17 with a 3.22 ERA and nine saves in 216 pitching appearances, including 29 starts, six complete games and one shutout, giving up 185 runs (161 earned) on 357 hits, while striking out 272 and walking 229 in 450+1⁄3 innings of work. In four minor league seasons, he had a 32–42 record with a 3.48 ERA in 111 games.