The longtime major league umpire who earlier this week sent a threatening tweet that included a reference to a rifle has apologized for the post.

In a statement to ESPN's Jeff Passan, Rob Drake expressed regret for the since-deleted tweet and said he'll learn from it.

"Once I read what I had tweeted I realized the violence in those words and have since deleted it," Drake said in the statement Thursday. "I know that I cannot unsay the words, but please accept my sincerest apologies."

Drake tweeted late Tuesday that he planned to buy an AR-15 rifle "because if you impeach MY PRESIDENT this way, YOU WILL HAVE ANOTHER CIVAL WAR!!! #MAGA2020."

The tweet, which he deleted soon after posting, followed one he sent earlier in the night regarding the House of Representatives' impeachment proceedings with President Donald Trump.

Drake deactivated his account Wednesday.

Commissioner Rob Manfred said Wednesday that Major League Baseball is looking into the tweet. The MLB Umpires Association on Thursday called Drake a "passionate individual and an outstanding umpire" who "chose the wrong way to convey his opinion about our great country."

"I want to personally apologize to everyone that my words made feel less safe," Drake said in the statement. "I especially want to apologize to every person who has been affected by gun violence in our country. I also acknowledge and apologize for the controversy this has brought to Major League Baseball, my fellow umpires and my family. I never intended to diminish the threat of violence from assault weapons, or violence of any kind."

Drake, 50, made his major league debut in 1999 and has been a full-time major league umpire since 2010. He worked postseason games in 2010 and 2012 through '15, and he was on the crew at the All-Star Game in 2013.

Born in Pennsylvania, Drake now lives in Arizona.