Great news for Josh Jacobs and the Raiders ... the massive gash the NFL star suffered on his forehead after crashing his car in Las Vegas last month is healing up well.
The running back showed off his face in videos on his social media page Wednesday ... and you can see, there's hardly any remnants of the huge cut that was so prevalent on his noggin just four weeks ago.
As we previously reported, Jacobs sustained the wound after wrecking his ride at around 4:42 a.m. on Jan. 4 near the Vegas airport.
Cops say when they came on to the scene ... they saw the 22-year-old was bleeding from a "large laceration" on his forehead. Officers added the injuries were so bad, Jacobs had to be transported to the hospital for treatment.
Jacobs -- who just hours before the crash had dominated in a game against the Denver Broncos -- was ultimately arrested over the wreck ... with cops believing he had been drinking prior to getting behind the wheel.
Prosecutors, though, announced just a few days after the accident they were NOT charging the NFL player with DUI ... and instead, hit him with one misdemeanor count of Duty of Driver to Decrease Speed Under Certain Circumstances.
Jacobs' attorneys, David Z. Chesnoff and Richard A. Schonfeld, said they were pleased with how the case was handled ... and, clearly, they're even happier to see Jacobs has appeared to have avoided any long-term physical trauma.