Witt has signed a two-year deal with the Otago Rugby Football Union and sought an early release from his Warriors contract.
The assumption is he will play first five-eighth or second five-eighth for Otago in the Air New Zealand Cup and then progress to the Highlanders, but Martin does not want to look too far ahead.
"Clearly he's a player of some ability. We're going to be very interested in seeing how he develops through the club season," Martin said yesterday.
"He's very much an unknown quantity in rugby and we need to see how he goes in the playmaking position.
It's too early to say where he's best placed.
Daniel Bowden and Chris Noakes played first five for Otago last year as the province slumped to 10th place in Martin's third year in the job.
While Bowden had signed for Auckland, that did not mean Noakes and now Witt were guaranteed selection, Martin said.
"We've also got a number of players we've been developing over the last few years - players like Glenn Dickson and Dan Snee, and Sam Young and Lex Kaleca in the [Otago]Country.
"Michael will need to win his place in the Otago team. It's fair to say that this is an opportunity for him to switch codes and see if he can make the grade.
"From our point of view, we get another player to develop within our ranks."
Otago has some options in the five-eighths but is desperately short of depth at fullback, with both Glen Horton (Southland) and Casey Stone (Manawatu) leaving the province.
That could prompt Martin to work on Noakes or Dickson as an option at the back while developing Witt as a five-eighth.
Witt has no experience of top rugby but Martin said his time in the National Rugby League had exposed his strengths.
"He's been involved as a playmaker for the Warriors. He's got vision for running a game and he's quite accomplished in defensive techniques. He's also a high-percentage goalkicker."
There is no official word on which club he will join but there is speculation he will play for Taieri in its return to the premier ranks.
That would give Taieri two former Warriors, with midfield back Ryan Shortland having joined the Mosgiel club over the summer.
