Keagle was selected in the sixth round, 170th overall, of the 1993 Major League Baseball Draft by the San Diego Padres. He was used almost entirely as a starter in the minors, appearing in only one game in relief before his first call to the majors. His first professional season in the Northwest League with the Spokane Indians was promising (3-3 record, 3.25 ERA), but the first half of his 1994 season was absolutely outstanding. He was 11-1 with a 2.05 ERA in 14 games for the Rancho Cucamonga Quakes and was named to the California League All-Star team. However, that success did not continue after he was promoted to the Double-A Wichita Wranglers, where he was 3-9 with a 6.27 ERA.
He remained in the Padres organization until September 17, 1995, when he was named as the player to be named later in a deal announced July 31 in which the Padres sent Andy Benes to the Seattle Mariners for Ron Villone and Marc Newfield.
In December of that year, the Tigers took him from the Mariners in the Rule 5 Draft.
Keagle was on the Tigers' Opening Day roster in 1996, and he made his debut in their first game of the season, April 1. He pitched three innings in his first big league game, surrendering three hits, walking two and striking out two. He allowed one earned run. His first career strikeout victim was Chuck Knoblauch. He then struck out Rich Becker, who followed Knoblauch in the batting order.
Keagle did not have a very successful rookie season. In 26 games (six started), he posted a three and six record with an ERA of 7.39. He also walked 68 batters in 87+ innings of work.
He was used mostly as a starter in the final two seasons of his career, 1997 and 1998. He went three and eight combined in those final two years, posting a career best ERA of 5.59 in 1998. He did not average five innings a start in his final two seasons.
Perhaps the best game of his career came on September 12, 1997, against the Oakland Athletics. He threw seven fine innings of work, giving up only five hits, one run (a home run to Scott Spiezio) walking only one and striking out nine batters.
Overall, his career record was six and 16. He posted an ERA of 6.76, and in 171 2⁄3 innings of work, he walked 106 batters and struck out 123. He pitched in a total of 46 games in his career, starting exactly half of those. He hit a total of 18 batters in his career, or one every 9.53 innings of work.
He had only one career at bat, facing Denny Neagle of the Atlanta Braves on September 2, 1997, he struck out. He committed zero errors in his career, for a perfect 1.000 fielding percentage. He played his final big league game on May 26, 1998. He wore number 57 during his time in the majors.
Although his major league career ended in 1998, his professional career lasted until 2005. He stayed in the Tigers' organization in 1999, split time between the Anaheim Angels organization and the Elmira Pioneers in 2000, where he threw the first no-hitter in Pioneers history (and just one of three in Northeast League history). In 2001 and 2002, Keagle was a pitcher/coach for the Pioneers. He played in the Florida Marlins organization in all of 2003.
He last played in 2005 with the Elmira Pioneers of the Can-Am League.
Overall, he spent six professional seasons as a teammate of Raul Casanova-longer than any other teammate.
Since retiring from professional baseball, Keagle has served his clients' financial needs for over a decade. As a Vice President of MassMutual New York State, Keagle is dedicated to the success and growth of both his clients and his team! He is responsible for developing and supporting those individuals who wish to serve their clients' comprehensive financial needs.
Greg has not forgotten his roots and he is fully aware of all that baseball has done for him. He now feels as though it is his duty to give back to the baseball community as well. He has been coaching for the Rochester Institute of Technology Tigers for the last 11 years. In 2010, he and his partner Rob Grow(head coach at RIT) started a youth baseball organization called the Grow2Pro Baseball Group. They are committed to providing an atmosphere that promotes teamwork and self belief! They teach that being a champion does not end when the game is over! Being a great teammate will serve them well in all stages of life and development. Keagle has also done color commentary for Rochester Red Wings live television broadcasts in Rochester, NY.
Greg Keagle currently resides in Pittsford, New York with his wife Danielle and their three children, Olivia, Jack, and Luke.