Matt Williams' future is one of many decisions Mike Rizzo faces

Nationals manager Matt Williams poor handling of Sunday's dugout fight between Jonathan Papelbon and Bryce Harper paved the way for deeper questions about the skipper's future when general manager Mike Rizzo addressed the media on Monday afternoon.

Following the melee in the eighth inning in which Papelbon lunged at Harper and then placed his hands on the superstar's throat, Williams sent Papelbon back out for the ninth inning of a 4-4 game against the Phillies because he's the Nats closer. Williams later said he didn't know what had actually transpired between the two high profile players.

"I thought it was odd," Rizzo said. "But there's a lot of things going on in the dugout at the time. Matt missed it. He owned up to it. He said it was his fault, if he had known he wouldn't have put him back in. His job is to manage that area in the dugout. And he made a mistake."

Whether Williams' obliviousness leads to far-reaching concerns for Rizzo is unknown. When asked about Williams' future as manager, Rizzo continued to deflect questions.

"We're going to make 2016 decisions after we finish 2015," Rizzo said. "He's under contract to be the manager next year."

Williams became one of the few men to be doubted immediately after coming off a National League Manager of the Year award. His questionable game decisions in last October's four-game National League Division Series loss to the Giants carried over into this season. Despite being prohibitive favorites to win the World Series entering this year, the Nationals failed to sniff the playoffs, realizing elimination with eight games still remaining in the regular season.

Rizzo did offer some slight insight on what Williams could have possibly done better this year.

"Possibly managed the health of the players better, or if we had a more stable lineup, he probably would have done a different job," Rizzo said.

The Nationals faced countless injuries throughout the year, playing with their projected opening day lineup for only two games. The ironic part is that Williams helped hold the Nationals in first place playing the likes of Clint Robinson, Danny Espinosa, Tyler Moore, Matt den Dekker and Joe Ross. But when veterans Jayson Werth, Anthony Rendon and Ryan Zimmerman returned from the disabled list, the Nationals quickly lost their division lead.

"I think Matt has persevered through a lot of different injuries, a lot of different ebbs and flows of the season," Rizzo said. "He's had to juggle maybe as many different lineups as any manager has in baseball and many injuries at different times and groups of players coming off the disabled list at the same time."

Rizzo wasn't interested in addressing a Washington Post report from the weekend in which one anonymous player claimed Williams has created "a terrible environment" in the Nationals clubhouse.

"If I knew who that person was, I would respond to it," Rizzo said. "When it's some blind accusation from an unnamed source, I don't react to those."

Added Rizzo: "We've got a bunch of tremendous veteran players in there and a combination of veteran players and good young kids that want to learn from those veteran players. We spent a lot of time working on the clubhouse culture and acquire players towards that end. I think the clubhouse is a good clubhouse. I think it's a positive clubhouse. I think it's a tight clubhouse."

Finally, Rizzo was asked to evaluate his own job in this season of disappointing results.

"I could say that the roster we put together in preseason, we felt it was a strong roster," Rizzo said. "You guys felt it was a strong roster. I think 17 of 18 of you picked us to win the World Series. So I think you guys thought we created ourselves a good, balanced, high-character and high-quality lineup. A lot of things went wrong. When things go wrong, you find out where your deficiencies are.

"Things went wrong quickly and they went wrong very often. Probably, I would say that, looking back at the season, when I look back at it, I'll probably see some things that I should have done different, that things that I didn't do. Everything rolls down from the general manager and the president of baseball operations' office. I take full responsibility for the quality of players that we put on the field. That goes from the 2009 season, when I took over, to after today's win."

I wonder how Rizzo will grade his decision-making at the trade deadline when he looks back. The Nationals owned a three-game lead over the Mets when New York acquired slugger Yoenis Cespedes minutes before the trade deadline expired. Two hours later, the Nationals began a three-game series at Citi Field resulting in a devastating sweep. The Nationals never sniffed first place again.

Cespedes followed the Mets' additions of versatile veterans Juan Uribe and Kelly Johnson, along with reliable right-hander Tyler Clippard. Meanwhile, Rizzo banked on his veterans returning from the DL with pop. When they eventually found their swings, the Nats' deficit was too great. And Rizzo's lone move - acquiring Papelbon - did nothing to help the Nationals reach the postseason.

In fact, it only added another problem to Rizzo's lengthy offseason list.