Pirates pitcher Felipe Vazquez will face a Pennsylvania judge Wednesday in his child sex case -- where he's expected to enter a plea to charges he sexually assaulted a 13-year-old girl.

TMZ Sports has obtained Vazquez's new mug shot ahead of his court hearing ... and, as you can see, the Pirates' All-Star closer has definitely seen better days.

Vazquez is facing 3 felony charges in Pennsylvania -- statutory sexual assault, unlawful contact with minor and corruptions of minors.

He's also facing 1 misdemeanor charge -- assault of a person less than 16.

As we previously reported, Vazquez is accused of having sex with a 13-year-old girl in his Mustang in Pennsylvania back in 2017.

Officials say the 28-year-old also sent the girl graphic videos and photos -- and told her in text messages he was planning to have sex with her again.

The texts were discovered by the alleged victim's mother -- who alerted police. Investigators say the images depicted numerous "unique and distinguishable" tattoos on his body ... which they were able to match to Vazquez through public images on the Internet.

Cops claim Vazquez admitted to the crime during a Sept. 17 interrogation ... telling investigators he had "sex but not really" with the victim.

Meanwhile, in Florida -- where the alleged victim claims she received the lewd text messages -- he's facing 2 felony charges ... 1) giving obscene material to a minor and 2) soliciting a child for unlawful sexual conduct.

A hearing in Florida has not been scheduled -- we're told officials will closely monitor the case in Pennsylvania before making any major decisions.

Vazquez is a 2-time All-Star who was having a great season for the Pirates in 2019. He currently has a 1.65 ERA, 28 saves and 90 strikeouts. He signed a 4-year, $22.5 million contract in 2018.