The 25-year-old right fielder earned $13,625,000 this year and agreed last May to a 2018 deal for $21,625,000.
"We had a meeting with the Washington ownership about a month ago just for some preliminary discussions," agent Scott Boras said Wednesday at the winter meetings. "It's probably something we'll address as time goes forward."
A long-term deal could top baseball's record, the $325 million, 13-year agreement by outfielder Giancarlo Stanton with Miami before the 2015 season. The Marlins traded the reigning NL MVP this week to the New York Yankees.
Boras usually prefers allowing players to become free agents before negotiating long-term contracts. He left open the possibility of reaching a new agreement before next season.
"That's up to ownership. So we'll have to look at it and report back to Bryce," Boras said.
A five-time All-Star, Harper hyper-extended his left knee landing on first base on a wet night Aug. 12 and did not return until Sept. 26.
Harper was the NL MVP in 2015, when he led the major leagues with 42 homers and hit .330 with 99 RBIs. He slumped to a .243 average with 24 homers and 86 RBIs in 2016, then rebounded to hit .319 with 29 homers and 87 RBIs in just 111 games this year.
"I frankly view it as a very simple process," Boras said. "When you have iconic players, they're different - they're different because you're not paying for performance value, you're acquiring a right to someone that generates revenue above what you pay him apart from his performance. So that iconic value is something that attaches to very few players in baseball and has to a few in the past, but it's certainly something that travels with Bryce."
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