Bryce Harper. (AP Photo/Seth Wenig)

NatsFest is the annual winter event meant to drum up excitement for the upcoming season. Fans buy tickets to see their favorite players and receive autographs. But this Saturday’s event featured one notable absence: Bryce Harper, arguably the most visible public face of the team.

The event, however, came at an unfortunate time. Harper and the Nationals are scheduled for an arbitration grievance hearing on Tuesday in New York. Three days before that potential hearing, Harper did not come to NatsFest at the Walter E. Washington Convention Center and General Manager Mike Rizzo took issue with that.

“We’re disappointed he’s not here,” Rizzo said, “but he chose not to be here because of the grievance.”

Those are strong words from the head of the Nationals’ front office. Earlier in the week, Rizzo acknowledged that the Nationals wanted to avoid a grievance hearing with Harper, who is represented by agent Scott Boras, because of the animosity it could create. Rizzo, however, wasn’t happy that Harper didn’t attend the fan event.

“I have attended NatsFest each year and always enjoy my experience with the fans, but was unable to attend this year’s event due to matters out of my control,” Harper said through his representatives. “I look forward to next year’s NatsFest.”

The dispute dates back to the day Harper signed with the Nationals. He has logged enough service time to qualify for arbitration as a “Super 2,” a player who ranks in the top 22 percent of players with between two and three years of service time. But Harper’s five-year major league draft contract, signed at the last minute before the deadline in August 2010, muddles whether he can become eligible for arbitration. Nearly all major league draft contracts used to include an opt-out clause that allowed players to enter the arbitration process rather than take the salary prescribed in their draft deal. But that is no longer allowed.

Given the choice, Harper would opt out of the deal and into arbitration. His draft deal stipulates he will earn $1.5 million in base salary in 2015. In arbitration, Harper is projected to make around $2.5 million.

The Nationals contend that an opt-out clause was not included in Harper’s contract and was agreed upon. Boras claims the Nationals orally agreed to include the clause at the midnight deadline in 2010. The difference in 2015 salary may  be a $1 million but, in arbitration, salaries compound each year and many more millions could be at stake.

Denard Span wasn’t at NatsFest but he underwent sports hernia surgery last week. Jayson Werth was at NatsFest but wasn’t made available to reporters like the rest of the players. Rizzo said he made that choice.

“Werth is here and he’s going to be all over the place,” Rizzo said. “We’ve got a lot of things scheduled for him … He’s going to be around and visit with the fans and I think that’s the important part of what he should be doing.”

Werth was convicted on Dec. 5 of reckless driving and was sentenced to 10 days in jail. Werth’s attorney said then he was planning to appeal the conviction.