Denver Broncos star Jonathon Cooper went before a judge to address his recent arrest ... with his attorney entering a not guilty plea and requesting a prompt resolution in the case.

Cooper -- who was expressionless in a black shirt and pants -- was present in a Douglas County courtroom on Monday ... where his lawyer, Harvey Steinberg, emphasized the importance of getting the matter taken care of so the linebacker can get back to his day job.

Cooper did not speak during the brief appearance. A motion hearing is set for early next month.

As we previously reported, Cooper is accused of getting into an altercation with his girlfriend, Jade Fiegen, late Thursday night over apparent cheating suspicions.

During the encounter, Cooper admitted to biting Fiegen's phone and damaging it ... while Fiegen told police he lifted her off her feet by the neck and pushed her to the ground. Cooper, on the other hand, claimed he braced his neck against Fiegen's to prevent her from getting his phone.

They were both arrested for criminal mischief and domestic violence and booked in jail.

Over the weekend, Cooper issued an apology alongside highlighted scripture ... saying, "I realize posting a Bible quote right after something very serious happens does not mean everything is okay. I apologize to my family to my friends and my community … and so many others."

"Sincerely I apologize. This situation is not who I am."