Stefon Diggs can focus on his day job now that a jury found him not guilty of attacking his personal chef ... and he did just that hours after his trial ended on Tuesday ... heading to the gym for a late-night sweat sesh.

The current free agent's buddy, music exec Steven Victor, shared a video of the star athlete running on a treadmill at 10 PM ... about six hours after he was exonerated in his strangulation and assault and battery case in Massachusetts.

Diggs' attorney, Mitchell Schuster, told reporters his client's goal is to get back on an NFL roster ... adding anyone would be "lucky" to have him join their team.

"People have to stop targeting professional athletes and trying to extract money," Schuster said outside the Dedham courthouse. "They have a target on their back."

As we previously reported, Diggs shed tears as the verdict was read ... as he maintained the alleged incident never happened.

The trial was a nightmare for Jamila Adams ... and the prosecution even admitted that much in closing arguments, when Norfolk Assistant District Attorney Drew Virtue said the chef was "argumentative, avoidant and difficult" during her testimony.

"Was Ms. Adams a perfect witness? No," Virtue said ... adding he was hoping the jury would look past that and focus on her side of the alleged incident.

The jury only needed about an hour and a half before finding Diggs not guilty ... and he can now get back to football.