The Blues need a director, or several of them, to fit all the pieces together, someone to "see" the field, take command, make the plays, and offer the right variation to bring out the best in his teammates.
Marshall wants that five-eighths job and is being drip fed into the nuances of the game.
All his rugby and league life he has played as first receiver and is used to the pressure of that role. The Blues staff were happy to agree to his request to play five-eighths and have left him there rather than muddle his thoughts with ideas about other positions.
The staff have given Marshall plenty of work inside the classroom and on the training field as initial preparation for this season. They have unpicked his game and taught him how to pass, where to stand and how to call his plays.
"Every day I'm learning something new - the way you defend from lineouts, the way you defend from scrums, where you stand after you kick the ball. It's a completely different way of thinking," he said.
The Blues coaches have decided not to overload Marshall in the trial games against the Hurricanes and Waratahs last night in Sydney.
Their logic seems to be to give Marshall enough match practice without overloading his thoughts. They want him to have a decent hit-out then think about how he reacted while watching a teammate do the business in the next half.
No one knows the best recipe and players react differently. Blues coaches John Kirwan, Mick Byrne and Grant Doorey have all played both codes so have that experience to draw on.
Most high-profile converts have been outside or midfield backs like Israel Folau, Sonny Bill Williams, Scott Gibbs, Daryl Halligan, Wendell Sailor, Matthew Ridge, Craig Innes and Marc Ellis.
There have been loose forward code-hoppers like Scott Gourlay, Mark Carter and the remarkable lock Brad Thorn.
Jonathan Davies, Ricky Stuart, Wally Lewis and Cooper Cronk were inside backs who went to league but few of any profile have swapped from league to rugby with much impact.
Perhaps with that in mind and the demands of a lengthy season ahead, the Blues have decided it is best to drip-feed Marshall into their plans. He will be keen to impress as injuries bite into the roster and that assessment will get a last pre-season rating when the Blues play the Chiefs next Friday in Rotorua.
