To date, no action has been taken against Cmdr. Greg Meyer, who was serving as commander of the squadron when the incident happened. He is no longer in a command job, but he is one of the seven who is facing possible discipline.
The official said that in addition to Rasch, Meyer and three of the detained sailors, there also may be action taken against an officer and an enlisted sailor who were based in Kuwait and had oversight of the boat teams.
Several other sailors have already received administrative reprimands in connection with the January incident.
The official was not authorized to discuss the matter publicly so spoke on condition of anonymity.
Iran detained the sailors, nine men and one woman, after their boat drifted into Iranian waters off Farsi Island, an outpost in the middle of the Persian Gulf that has been used as a base for Revolutionary Guard speedboats since the 1980s.
The sailors were on two small armed vessels, known as riverine command boats, on a 300-mile journey from Kuwait to Bahrain, where the Navy's 5th Fleet is located. The incident, while brief, raised tensions between the U.S. and Iran because of images Iran published of the soldiers kneeling with their hands on their heads. It caused political uproar at home, too, coming on the day of President Barack Obama's final State of the Union address and months after the signing of a deal with Iran to curb its nuclear program in exchange for relief from financial penalties.
An early account of the incident said the crew stopped when a diesel engine in one of the boats appeared to have a mechanical issue. The second boat also stopped.
At that point they were in Iranian territorial waters, "although it's not clear the crew was aware of their exact location," the report said.
While the crew was trying to assess the mechanical problem, two small Iranian craft carrying armed personnel approached, and later two more Iranian military vessels arrived. A verbal exchange ensued between the Iranians and Americans, but there was no gunfire.
The sailors were taken onto Farsi Island.
Secretary of State John Kerry, in a series of phone calls, used the personal relationship he has formed with Iranian Foreign Minister Mohammad Javad Zarif to work out the crews' release.