Cowboys and Queensland halfback Johnathan Thurston could miss the Harvey Norman State of Origin decider in Brisbane on July 6 after he was today charged by the NRL’s Match Review Committee with Grade 2 contrary conduct for contact with a referee.

Thurston made contact with referee Matt Cecchin in the 23rd minute of the Cowboys' win over the Warriors on Saturday.

The influential halfback is facing two weeks on the sidelines, even with an early guilty plea.

The charge follows amendments to contrary conduct rules implemented at the start of the season where either Careless, Reckless or Intentional contact with a Match Official can be charged as Contrary Conduct.

Under the rule, “It’s the responsibility of the player to avoid contact with match officials at all times during a match”.

In the event that the Cowboys challenge either the grading or the charge, a judiciary hearing will be held on Wednesday night at NRL Headquarters in Moore Park.

If Thurston pleads not guilty and is successful at the judiciary, he will be free to play in the Cowboys’ Round 16 clash against the Panthers at Penrith on Sunday.

A guilty verdict would rule him out of that game as well as State of Origin.

Thurston also has the option to challenge the grading and, if successful at the judiciary, he would miss the Cowboys’ match against Penrith but would be free to take his place against NSW.

Thurston and the Cowboys will have until midday tomorrow to notify the NRL of their decision.

Fellow Cowboy Tariq Sims is also facing a week on the sidelines after he was charged with Grade 2 Dangerous Contact on Warriors' Krisnan Inu.

Sims would miss a week with the early guity plea or two weeks if he challenges the charge and loses at the judiciary.

Melbourne's Sika Manu will avoid suspension with an early plea after he was charged with Grade 1 Dangerous Contact on Wests Tigers Gareth Ellis.