Questions remain over plans to introduce Covid testing at points of entry to the isles.
Chief executive of NHS Shetland Michael Dickson has questioned the logistics behind the move, which has been championed by isles MSP Beatrice Wishart.
It follows an assurance on Friday from the Scottish government that it would support the measure.
Mr Dickson said: “We appreciate the community feels strongly that testing should be available at points of entry and exit into the island communities and we welcome the political commitment to support this.
“At this very early stage the logistics of how this will be done need to be worked out and discussed.
• Who would carry out the testing?
• Where would this take place, as proposals would require multiple health boards and transport companies?
• How would positive cases be managed and isolated?
• Would this apply to all entry and exiting individuals, including freight and fishermen?
• How would we manage travellers who decline a test?
“All of this must be discussed before firm proposals can be submitted to the Scottish government for consideration.
“This is not as simple as some may portray. If it is to be introduced, it must work well so the public can have confidence in it.
“And, if the Scottish government introduced mandatory testing, it would require a multi-agency partnership across the islands and mainland agencies.”
Council leader Steven Coutts said any testing strategy should be developed by NHS Shetland as “lead agency”.
He added the council would “assist with the operational delivery and logistics where such support is needed”.
“For example, we did this with the mass testing at Gilbertson Park and are continuing to do this with the vaccine programme.”