Since retirement, Dykstra has been mired in financial and legal troubles. In , he filed for bankruptcy. In , he was arrested and charged with bankruptcy fraud , followed by grand theft auto and drug possession charges on an unrelated case, as well as indecent exposure.
Dykstra's mother, Marilyn, later married Dennis Dykstra, a phone company employee. During his senior year, he hit. He had a career total of 89 stolen bases, second best in state history at the time, and recorded a hit in all 27 games of his senior season. In both his junior and senior seasons he was named all-league, all-county, and all-state. Dykstra was originally committed to play baseball at Arizona State University for Jim Brock but said he would sign to play professionally if drafted high enough.
A star in the minors , in he led the Carolina League in at-bats , runs , hits , triples , batting average and stolen bases. That season, he hit. While playing in Double-A in he befriended fellow outfielder and teammate Billy Beane , who later said that Dykstra was "perfectly designed, emotionally" to play baseball and that he had "no concept of failure.
In , Dykstra was promoted to the Mets when the team's starting center fielder , Mookie Wilson , was placed on the disabled list. The rookie's play and energy was a big boost to a Mets team that surged to a win season and narrowly missed out on the NL East crown. The following season, Dykstra was intended to be platooned in center field with Wilson, but took over the position as outright starter and leadoff hitter when Wilson suffered a severe eye injury during spring training.
As the season progressed, Wilson began to get more playing time in left field, as the incumbent leftfielder , George Foster , was struggling, eventually getting released. This allowed Dykstra and Wilson to start in the outfield together, along with star rightfielder Darryl Strawberry. Dykstra earned the nickname "Nails" for his hard-nosed personality and fearless play. Also in , Dykstra posed shirtless for a "beefcake" poster under the "Nails" nickname. Dykstra and 2 hitter Wally Backman were tagged as "The Partners in Grime" for their scrappy play as spark plugs for the star-studded Met lineup.
