Hammond, a left-handed pitcher, was drafted out of UAB in the sixth round of the 1986 draft by the Cincinnati Reds, making his first appearance in 1990. He compiled a 14-19 record over parts of three seasons, and was traded to the Marlins for Gary Scott and Hector Carrasco just prior to their inaugural season in 1993.
Hammond posted an 11-12 record with the Marlins that first year with a 4.66 ERA in 191 innings. He also hit two home runs in 63 at bats.
Followed by an injury and strike shortened 1994, Hammond rebounded a bit in 1995, compiling a 3.80 ERA to go with a 9-6 win loss record over 25 games. He finished in the NL top ten in K/9 with 126 strikeouts in 161 innings.
Hammond later played for the Boston Red Sox for one season before rejoining the Marlins for the 1998 season. He retired after going 0-2 with a 6.59 ERA in three starts and struggling with injuries.
In 2002, Hammond came out of retirement to play one season each with the Atlanta Braves, the New York Yankees, the Oakland Athletics and the San Diego Padres. He would rejoin the Reds for the 2006 season. As a reliever, post-retirement, Hammond posted a 20-7 record over five Major League seasons with a 2.93 ERA.
For Florida, Hammond won 29 games against 32 losses to go with his 4.52 ERA. He struck out 332 in 520 innings while walking 171.