Nationals GM Mike Rizzo said that club was "disappointed" that outfielder Bryce Harper did not show up Saturday at the NatsFest fan festival.

In a statement emailed by one of his agent's employees, Harper said: "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. I look forward to next year's NatsFest."

The MLBPA has filed a grievance on Harper's behalf over whether he should be able to void the 2015 terms in the final season of a $9.9M, five-year contract he signed when drafted.