FORT BRAGG, N.C. (AP) — A top Army general is scheduled to testify about why he destroyed letters he received from supporters and critics of Sgt. Bowe Bergdahl.

Gen. Robert B. Abrams is scheduled to appear in court Wednesday at a pretrial hearing to answer questions related to a motion seeking to disqualify him from the case. Abrams is the four-star head of U.S. Army Forces command who decided to send Bergdahl's case to a general court-martial rather than a lower-level tribunal. Abrams has acknowledged that he disposed of letters on the case by sending them to an incinerator.

Bergdahl, who's from Hailey, Idaho, walked off his post in Afghanistan in 2009 and wound up as a captive of the Taliban and its allies until 2014. He faces a court-martial on charges of desertion and misbehavior before the enemy.

Prosecutors say defense attorneys for Army Sgt. Bowe Bergdahl have invented a legal issue by arguing the case was tainted by comments from U.S. Sen. John McCain. The defense wants the charges against Bergdahl to be thrown out because of "impermissible meddling" by McCain, who chairs the Senate Armed Services Committee. McCain has said the panel would hold a hearing if Bergdahl weren't punished.

But Maj. Justin Oshana, an Army prosecutor, argued Tuesday that no other court has ever made a ruling similar to what the defense is seeking. The judge, Army Col. Jeffery Nance, quipped that he wasn't sure he wanted to be the first either. But he said he would consider the motion and rule at a later date. Bergdahl faces military charges after walking off his post in Afghanistan in 2009. He became a captive of the Taliban and its allies until 2014.