Williams and Rizzo also worked together when the D-backs won the World Series in 2001. Williams was the everyday third baseman while Rizzo was the scouting director.
Both Rizzo and Williams were not available for comment.
Ausmus' interview took place on Tuesday and it went well, according to a baseball source. Ausmus is currently a special assistant for the Padres. But he was best known as one of the top defensive catchers in baseball during the 1990s and early 2000s. He won three Gold Glove Awards with the Astros and helped Houston reached the World Series in 2005.
In 2012, Ausmus was considered a managerial candidate for the Astros, but withdrew his name from consideration. The job eventually went to Bo Porter.
A baseball source who is familiar with Rizzo's thinking believes Williams is on top of the Nats' managerial list, followed by Randy Knorr and Rays bench coach Dave Martinez, who has not interviewed for the position. Nationals third-base coach Trent Jewett is also a candidate.
Of the current players on the club's Major League roster, Knorr managed 11, including Ryan Zimmerman and Stephen Strasburg, in the Minor Leagues.
In 2008, while managing Class A Advanced Potomac, Knorr guided the team to the Carolina League championship.
Knorr is also not afraid to speak his mind. While filling in for Johnson last August, Knorr called outfielder Bryce Harper out for not hustling against the Mets. In a game against the Pirates on July 26, Knorr quickly yanked closer Rafael Soriano out of the game in the ninth inning as he struggled with command.
"I think it's very important to speak your mind," Knorr said in September. "Your players will never be in the dark in what you believe in. I don't have secrets with my players. They ask me a question, I'll be as honest as I can with them. You have a better relationship with them. They are not always trying to figure you out. ... They know where you are coming from, they have no problems with it."
On the last day of the '13 season, shortstop Ian Desmond made it known that he wants Knorr to be the manager.
Knorr and Desmond have a player-manager relationship that dates to when both were with Class A Savannah in 2005.
"It pretty evident that [our relationship] goes back a long time," Desmond said. "He has been a tremendous influence on my career. For me to say anybody else but Randy would be a lie. That's who I want to see as manager of the ballclub.
"With that being said, I wouldn't ever doubt any move that Mike Rizzo makes. Since I've been here, I've seen the progress that we've made under his [leadership]. The team has only gotten better. I can't think of a move that he made that hurt our team. He has done an unbelievable job. I would respect anyone that he brought in. I, as a player, think that Randy is the best fit for us."
Martinez has been the bench coach for the Rays since 2008. He also serves as a baserunning and bunting coach. He is best known as an outfielder with nine teams including the Cubs, Expos and Giants from 1986-2001.
Jewett, who was Washington's third-base coach last year, once interviewed for the managerial job after the Nationals relieved Frank Robinson of his duties in 2006, but the job went to Manny Acta.
Jewett has been with the Nationals since 2009. He was a manager for Potomac and then Triple-A Syracuse before joining the big league club in 2011.
Other managerial candidates are Dusty Baker and Cal Ripken Jr., but they have not yet talked to Rizzo.