After a disappointing end to their season, the Nationals will be without one of their top front-office people next season. (Jonathan Newton/The Washington Post) After a disappointing end to the season, Nationals assistant GM Bryan Minniti announced he was leaving the organization. (Jonathan Newton/The Washington Post)

Three days after the Nationals’ season ended, assistant general manager Bryan Minniti announced in an e-mail to counterparts and friends that he is leaving the organization after five years.

The move is surprising, as the Nationals’ front office wasn’t expected to undergo any changes after an early playoff exit.

Minniti joined the Nationals in 2009 as an assistant general manager and was a well-liked member of the front office. He handled everything from contracts to helping with daily operations of the team.

“After five productive years with the Washington Nationals, it’s time for a change, so I’m leaving the organization,” Minniti wrote in his e-mail sent out Friday evening.

Minniti added that he is uncertain what is next for him, suggesting the next step could be outside of baseball. He did not immediately respond to a message seeking comment.

Minniti spent nine seasons with the Pittsburgh Pirates before joining the Nationals. He had been a constant in the Washington front office, playing a role in helping guide the Nationals’ rise from the bottom to the top of the National League East.

“Bryan has been an integral part of my staff for the past five years,” General Manager Mike Rizzo said in a written statement. “The success we’ve had as an organization, building from 100-loss team to one that has captured two NL East Division Championships in the last three years, would not have been possible without him. He was a tireless worker and a trusted advisor. On behalf of the organization, I wish him nothing but the best in the future.”