"Until then, we're just going to leave it that he's going to get a second opinion," Huntington added.
If Kingham is injured for a significant period of time, it would be the second blow to the Pirates' rotation depth this year, as right-hander Brandon Cumpton -- the presumed next man up in the event of an injury -- underwent Tommy John surgery this spring.
But the Pirates remain confident in their pitching depth. They already have a strong five-man rotation, and right-hander Charlie Morton is nearing a return to the rotation, as he's scheduled to make his second Minor League rehab start on Thursday for Indianapolis.
Huntington listed Adrian Sampson and veteran lefty Clayton Richard as further rotation insurance, if there's a need.
"We'll see where Nick Kingham takes us and how long he's going to be down for. Obviously, he's going to be down for a while," Huntington said. "We've chipped away at our depth, and we're going to have to have some guys continue to grow and develop.
"We may need to add, depending on where we go. It's going to factor into our roster decisions moving forward. But again, the ability to add a Charlie Morton here sooner [rather] than later certainly is a nice addition."
Richard made his season debut for Class A Advanced Bradenton on Thursday, and the Pirates are in the process of determining where he'll make his next start.
Right-hander Jameson Taillon, the Bucs' No. 2 prospect, is facing hitters, but has yet to appear in a game as he continues to work in extended spring training at Pirate City in Bradenton, Fla.
"We're working him through a very slow and a very conservative progression because of our belief in what it takes to come back from Tommy John -- some scientifically proven, some anecdotally discovered," Huntington said. "[Taillon is] making great progress, and we're looking forward to him having a strong second half and being in position to help us when he's ready to go."
The Pirates did manage to avoid bad news for No. 1 prospect Tyler Glasnow, who left his last start with a right ankle sprain. Glasnow is feeling good and still considered day-to-day, Huntington said.
• The Pirates acquired left-hander Jayson Aquino from the Blue Jays on Sunday in exchange for cash considerations. Aquino, designated for assignment by Toronto on May 5, was optioned to Bradenton. The 22-year-old went 2-2 with a 2.81 ERA in five starts this season for Class A Advanced Dunedin.