[1] During his active career (1993–1999; 2002), Henley threw and batted right-handed; he stood 6 feet 2 inches (1.88 m) tall and weighed 190 pounds (86 kg).

He graduated from Mobile County High School in Grand Bay, Alabama, and was selected in the 26th round by the Montreal Expos (predecessors to the Nationals) in the 1991 Major League Baseball draft.

He spent the early part of the season on the disabled list, and then appeared in 50 minor league games with the Triple-A Ottawa Lynx and the Class A Jupiter Hammerheads before making his MLB debut as a defensive replacement in the eighth inning of a 6–1 loss to the Pittsburgh Pirates on July 19 at Olympic Stadium.

He walked in his first MLB plate appearance,[3] and, the following day, when he started against the Philadelphia Phillies, he singled off Curt Schilling in his first official at bat.

He amassed 35 hits and 11 walks in 132 plate appearances, batting .304 and collecting three homers (off Pedro Astacio, Kirt Ojala and Bobby Jones) and eight doubles.