Boone added the situation is "still kind of a gray thing" after Hicks got a second opinion on his elbow from Dr. Neal ElAttrache.
"We're trying to get as many smart people as we can looking at this," Boone said. "But it's frankly something that's not real clear as what the course of action should be."
ElAttrache and team physician Christopher Ahmad could not confirm if Hicks needs the procedure on his ulnar collateral ligament.
"When you look at how they read the MRIs, it's not clear that something needs to be done," Boone explained. "The reality is that he hasn't responded yet to the first shutdown and how he came back. Hopefully, we'll all make the right choice in time here."
Next steps won't be determined until after a few weeks of rest and then re-evaluation, according to Joel Sherman of the New York Post.
Even in a best-case scenario, it's increasingly unlikely Hicks will return to the Yankees this season, including for the playoffs, Sherman added.
The 29-year-old Hicks suffered a setback in his recovery last week, prompting the second opinion. He's been out of action since sustaining the injury against the Boston Red Sox on Aug. 3.
This season, Hicks has slashed .235/.325/.443 with 12 home runs and 36 RBIs in 59 games after signing a seven-year contract extension in February.