Trout, the reigning American League Rookie of the Year, batted .326 with a .399 on-base percentage, 30 home runs, 129 runs and 49 stolen bases last season.
Under salary rules, players with less than three years of service have little leverage, and teams can renew their first year's salary if they can't come to terms on a new deal.
The Angels and Trout are reportedly far apart in contract negotiations.
But the team's decision to assign Trout a 2013 salary of $510,000 --- only a $21,000 more than the MLB minimum -- despite turning in one of the best first-year performances in baseball history last season has rankled his agent, the Los Angeles Times reported.
"During the process, on behalf of Mike, I asked only that the Angels compensate Mike fairly for his historic 2012 season, given his service time," Craig Landis said in an email. "In my opinion, this contract falls well short of a 'fair' contract, and I have voiced this to the Angels throughout the process."