Born in Lakeland, Florida, on October 18, 1966, Mills was the youngest of Hugh and Alfreddia Mills' four children. His favorite sport in his youth was football, but he switched to baseball after doctors informed him that he had only one kidney. He graduated from Kathleen High School in 1984. He was an outfielder on the school's varsity team before making the transition to pitcher. He attended Tuskegee University, but transferred to Polk Community College after one year when the former dropped baseball scholarships. He was selected in the MLB Draft on two occasions in 1986, both times in phases that were discontinued later that year. He was chosen by the Boston Red Sox and California Angels in the first rounds of the regular phase of the January draft and the secondary phase of the June draft respectively. He decided to sign with the Angels over the Red Sox based on which team was willing to finance his final two years of college. Mills spent just one season with the Salem Angels of the Northwest League, compiling a 6-6 record over fourteen starts, before the Angels sent him to the New York Yankees to complete a December 19, 1986, deal in which the Yankees sent Butch Wynegar to the Angels for Ron Romanick and a player to be named later.
New York Yankees
Mills converted to a relief pitcher during his three seasons in the Yankees' farm system, going 12–24 with a 4.25 ERA and thirteen saves. With the Prince William Cannons of the Class ACarolina League in, Mills went 6–1 with a 0.91 ERA and seven saves to lead his team to their first Carolina League title. Though he had never pitched above A ball, his performance earned him and invitation to Spring training in. He made his major league debut on April 14, pitching 2.2 scoreless innings against the Texas Rangers. Mills went 1–5 with a 4.15 ERA his rookie year splitting his time between the Yankees and triple AColumbus Clippers. For Columbus, he was 3–3 with a 3.38 ERA and six saves. Mills spent most of in the minors, however, made two starts upon returning to the club in September. He was traded to the Baltimore Orioles for a player to be named later during Spring training the following season. As of 2012, Mills is the only Yankee to wear number 69 in a regular season game.
Baltimore Orioles
Mills emerged as a valuable member of the Orioles' bullpen upon his arrival in Baltimore. He went 10–4 with a 2.61 ERA over 103.1 innings in. Mills made a team high 72 appearances in, going 3–4 with a 3.74 ERA. Perhaps the most famous moment of Mills' career came on May 19,, when he gave Darryl Strawberry a right cross that bloodied his face in the dugout during a bench clearing brawl with the New York Yankees at Yankee Stadium. Strawberry had just hit Mills' teammate Armando Benítez with a cheap shot during a melee, and Mills promptly defended Benitez by clocking Strawberry point-blank. The following season, Mills signed as a free agent with the Los Angeles Dodgers. After a season and a half in Los Angeles, he was dealt back to the Orioles for Alberto Reyes. He remained with the Orioles through before being released. In a 12-season career, Mills posted a 39–32 record with 456 strikeouts and a 4.12 ERA in 474 games. Mills wore jersey number 75 with the Orioles. Numbers that high are typically only worn by players in spring training. Mills chose to wear it as a motivating factor, to remind himself that his job was not necessarily any more secure than that of someone in spring training should he perform poorly.
Mills attempted comebacks with the Montreal Expos in Spring training and the Tampa Bay Devil Rays in, but was essentially away from the game for five years before signing a minor league deal with the Detroit Tigers in, and spending one season with the Erie SeaWolves. In his first 27 games, he went 23-for-23 in save opportunities, posting a 1.65 ERA and limiting batters to a.154 batting average.
