Lenny Dykstra -- Jail Time for Craigslist Knife Attack

More slammertime for disgraced baseball star Lenny Dykstra ... Nails has just been sentenced to 3 months in L.A. County Jail for allegedly holding a knife to a woman's throat.

Dykstra pleaded no contest to charges of assault with a deadly weapon and lewd conduct this morning ... for incidents involving women he lured to his home by posting ads for a housekeeper on Craigslist.com.

Officials tell us ... when the women would arrive to his home, Dykstra would inform them the job required them to give him a massage ... and then he would expose himself.

Dykstra allegedly ran the scheme at least 6 times ... and during one of the incidents, officials say he held a knife against a woman's throat and forced her to massage him.

In exchange for his plea, Dykstra was sentenced to 3 months in jail and 3 years probation.