Jeffrey Bruce Keener (born January 14, 1959) is a former Major League Baseball player, who appeared as a relief pitcher in two seasons with the National League’s St. Louis Cardinals.
Drafted from the University of Kentucky in the seventh round of the 1981 Major League Baseball Amateur Draft, Keener quickly progressed through the Cardinal farm system.
Keener made his Major League debut at the age of 23 on June 8, 1982 at Montreal’s Olympic Stadium against the Cardinals National League East rivals, the Montreal Expos. Keener retired all four batters, two of them on strikeouts, en route to a 5-4 Cardinal victory. In a total of 19 appearances during the 1982 season, he compiled an earned run average (ERA) of 1.61, with 25 strikeouts, 22 walks, and a record of 1 win, 1 loss, 0 saves.
During the 1983 season, Keener appeared in just four games with the Cardinals, posting an ERA of 8.31. His final appearance, September 27, 1983, marked his final game in the Major Leagues.
Despite his short tenure in the big leagues, Keener is remembered for his unusual “submarine” delivery, with which he delivered pitches with a sidearm/underarm motion, rather than over the shoulder.