Watch: Platoon leader of Bowe Bergdahl slams 'desperate attempt' to seek Obama pardon

The onetime platoon leader of embattled Army Sgt. Bowe Bergdahl offered a strong rebuke of the former Taliban prisoner Monday after it was recently made public that Bergdahl would formally ask President Barack Obama for a pardon prior to the president's leaving office next month.

Bergdahl went missing in June 2009 while on deployment in Afghanistan and was released in May 2014 as part of a prisoner swap between the U.S. and the Taliban. How Bergdahl went missing and how he was captured by the Taliban remains shrouded in mystery.

However, in late 2015, the U.S. Army announced that it was charging Bergdahl with "desertion" and "misbehavior before the enemy" and that he would face a general court-marital. Bergdahl's trial is set for sometime early next year. If found guilty, Bergdahl could face life in prison.

In an interview with Fox News' "Fox and Friends" Monday, retired U.S. Army Sgt. Matt Vierkant, Bergdahl's platoon leader at the time he disappeared and was captured by the enemy, slammed Bergdahl and his "desperate attempt" to escape his serious charges.

Vierkant alleged that Bergdahl is making the request because he and his attorneys do not have an actual legal defense for him.

"They don't have a leg to stand on," Vierkant said.

"The bottom line is he has to be accountable for his actions," Vierkant said. "It's nobody's fault but his that he was put in that position, so he has nobody to blame but himself. And it's unfortunate that he was a prisoner for five years, but it's his own fault."

But Bergdahl's defense team has said in recent weeks that he wouldn't get a fair trial under the administration of President-elect Donald Trump, citing comments Trump made in August 2105 and December 2015 when he labeled Bergdahl a "dirty, rotten traitor" and a "dirty, rotten deserter."

But for Vierkant, Trump's opinions do not matter. What does matter, however, is the professionalism of the U.S. military.

"I believe we should let the military be professionals who conduct themselves in a professional manner and hold the trial," he said, "because [Trump's] opinion isn't going to affect it any more than my opinion or anyone else's."