Troy O'Leary was originally an outfield prospect in the Milwaukee Brewers organization. Milwaukee gave him a couple shots in 1993 and 1994 and then tried to pass him through waivers to send him down to the minors in 1995. Boston swooped in at that time and grabbed him. It was not long before he became the team's regular right-fielder, especially as Mark Whiten was struggling badly.
O'Leary had a good year in 1995 during his first season with the Red Sox. He hit 10 home runs and had a slash line of .308/.355/.491/.846. Not bad for a player in his first real shot at the Major Leagues. He also played pretty good defense. In 1996, he played the full season and slipped a little bit. He did increase his home run total to 15, but his overall numbers dropped and he did not play well in the outfield that year.
In 1997, O'Leary's numbers were back up to his 1995 levels, while his home run numbers stayed constant. He was entering the prime of his career and looked like a solid outfield option for years to come. In 1998, his power numbers took a step forward as he hit 23 home runs with 83 RBIs. He also moved over to left field and improved his defensive play. In 1999, he lead the team in home runs with 28 and drove in 103.
In the 1999 ALDS against Cleveland, O'Leary had his career highlight. In the fifth and final game of the series, Cleveland twice intentionally walked Nomar Garciaparra to pitch to O'Leary. Each time, there was at least one other runner on base. Each time, O'Leary smashed a home run to drive in seven runs in the game. He was as big a part as Pedro Martinez in winning that game.
In 2000, O'Leary started to slide. He would only hit 13 home runs each of the next two years and his RBI numbers and batting average slipped. He left as a free agent to Montreal in 2002.
For his Red Sox career, O'Leary hit .276/.331/.459/.791 with 117 home runs.