Dallas Cowboys star Micah Parsons is apologizing for slamming President Joe Biden over the Brittney Griner deal ... admitting he was speaking "out of emotion" and wasn't educated on the topic.
The 23-year-old was livid after the Griner news broke Thursday morning ... solely because retired Marine Paul Whelan has been behind bars in Russia since 2018 after being accused of spying.
Parsons -- whose father is a military vet -- was irked after finding out Whelan wasn't part of the deal to bring BG home ... saying, "Wait nah!! We left a marine?!! Hell nah."
The 2021 first-round pick clarified he was thrilled Griner was on her way back to U.S. soil ... but explained, "I just have family who have served and it’s crazy to me the President wouldn't bring him home too."
"I'm the furthest thing from a Trump supporter but I'm not a fan of Biden either."
Parsons later backpedaled on his stance ... saying he talked things over with some people and now has a better understanding of the situation.
"I should have been more educated on the topic and not tweeted out of emotion for my family and other who have served," Parsons tweeted. "For that I apologize."
"Also if what I'm told about the attempts to bring Ret Marine Paul Whelan home are true then the best outcome was accomplished. I pray Mr. Whelan comes home but am extremely happy for Brittney and her family."
"I am not too prideful to admit when I've made a mistake."
The White House said the U.S. tried like hell to include Whelan in the Griner deal ... but ultimately, Russia wasn't going to budge.