Jonathan Papelbon's season over after scuffle with Bryce Harper

And the team also said that Papelbon has dropped his appeal against the three-game suspension he was given by Major League Baseball for hitting Manny Machado of the Baltimore Orioles with a pitch last Wednesday.

Papelbon, whom the Nationals acquired from Philadelphia in a July trade, has therefore played his last game for the team this season.

His scuffle with Harper happened during the eighth inning of Sunday's 12-5 loss to the Phillies.

Harper, who is a leading contender for the National League MVP award, was shouted at by Papelbon for what he believed was Harper's failure to run hard when he hit a fly-out.

The two exchanged words and Papelbon then lunged at his team-mate, grabbing Harper's throat and shoving the outfielder back toward the bench, before colleagues pulled the duo apart.

The incident capped a disappointing season for the Nationals, who began the year with World Series aspirations but have failed to make the play-offs.

Nationals General Manager Mike Rizzo said: "What happened was unacceptable.

"I think this was an isolated incident, and I think Jonathan will learn from this and react differently the next time."

Manager Matt Williams added: "I was upset, I was appalled.

"It has been a very difficult 24 hours for the organization. We have to get past that. We have to fix it, we have to move forward."