Former CIA Director John Brennan once again took a shot at President Trump on Twitter Thursday, saying he believes the decision to nominate Adm. Ronny Jackson to run the Department of Veterans Affairs is "terribly misguided."

"I personally know and greatly respect Ronny Jackson....as a terrific doctor and Navy officer," Brennan tweeted. "However, he has neither the experience nor the credentials to run the very large and complex VA. This is a terribly misguided nomination that will hurt both a good man and our veterans."

Trump announced via Twitter Wednesday his intention to replace current VA Secretary David Shulkin with Jackson, a 50-year-old Navy rear admiral who has served as personal physician to the president since 2013, when he was appointed by former President Obama, after being tapped to serve as a White House doctor in 2006.

RONNY JACKSON PICKED BY TRUMP TO LEAD THE VA: WHAT TO KNOW ABOUT THE PRESIDENT'S PHYSICIAN

Jackson's also a veteran. He was deployed to Iraq after he joined the 2nd Marines in 2005, according to his Navy biography.

Jackson's nomination triggered some concern among lawmakers and veterans groups about his experience to manage a federal agency, but Trump praised the lifelong doctor as "highly trained and qualified."

Trump decided to oust Shulkin from his Cabinet after he served just over a year in office. An internal VA watchdog found last month that Shulkin improperly accepted Wimbledon tennis tickets and that his then-chief of staff had doctored emails to justify his wife traveling to Europe with him at taxpayer's expense.

The swipe from Brennan, now an analyst for NBC News and MSNBC, isn't the first he's made against Trump.

Just last week, he suggested that the Russians "may have something" against the president, and days prior to that in response to former FBI official Andrew McCabe's firing: "When the full extent of your venality, moral turpitude, and political corruption becomes known, you will take your rightful place as a disgraced demagogue in the dustbin of history."

Fox News' Kaitlyn Schallhorn and Elizabeth Llorente, along with The Associated Press, contributed to this report.