They were discovered near Surtainville on France’s Cotentin Peninsula, on Monday, by French authorities.
Following this, the Air Accidents Investigation Branch (AAIB) has identified an area of four square nautical miles for a search.
The plane disappeared with Sala, 28, and pilot David Ibbotson, from Crowle, North Lincolnshire, on board last week.
Due to weather and sea conditions, an underwater search is not expected to start until the end of the week and will take up to three days, an AAIB spokesman said.
It will use sonar equipment to locate any wreckage on the sea bed.
French safety authorities found the two seat cushions, which preliminary examinations suggested were likely from the missing aircraft.
Following this, detailed assessments of the flight path and last known radar position were carried out, which identified the search area.
Through the Ministry of Defence’s salvage and marine operations team, a special survey vessel has now been commissioned to look for wreckage.
If it is found, a remotely operated vehicle will be sent down to examine it.
Argentinian Sala signed for Cardiff City and was travelling from Nantes, where he previously played, when the flight was lost over the English channel.
An official search for it was called off with Guernsey officials saying there was little chance those on board survived, however, more than £290,000 was raised for a private search to continue.
“We are aware that a privately operated search is also being conducted in the area,” an AAIB statement said.
The privately funded search for the plane carrying Emiliano will be conducted, on behalf of the Sala family, in close coordination with the AAIB search effort. The two vessels will work together to search the designated area as safely, completely and efficiently as possible.
— David Mearns (@davidlmearns) January 30, 2019
“And we are liaising closely with those involved to maximise the chance of locating any wreckage and ensure a safe search operation.”
Marine scientist David Mearns, who is spearheading the private search and is a Sala family spokesman, tweeted that both vessels will work together as “safely, completely and efficiently as possible”.