EXCLUSIVE

Ty Lawson has some serious explaining to do ... because officials in Denver believe the Sacramento Kings star violated his probation and are gunning for a warrant, TMZ Sports has learned.

Lawson is currently on probation stemming from his 2015 drunk driving case in Denver -- but the Denver Probation Dept. has filed a complaint seeking to revoke his probation citing a potential violation.

Officials would not say what the alleged violation is ... but confirmed to TMZ Sports that a bench warrant has been requested so they can bring Lawson to court for a hearing on the matter.

We're told a judge has not signed off on the warrant at this point.

Some of the requirements of Lawson's probation -- which was scheduled to end on March 22 -- included monitored sobriety, 48 hours of community service, 52 hours of therapy and no marijuana use.