Bryce Harper remains under control of the Washington Nationals for another four years, but the two sides might start clashing over contract issues in the near future. MLB sources say a grievance hearing may occur this month.

The Nationals probably didn't think this would be an issue back when Harper signed with the team in August of 2010. Before Harper signed the contract after being drafted in June, not everything was in writing, specifically whether or not he could opt out and enter the arbitration system to potentially earn more money. This is exactly what might be debated in the grievance hearing.

Adam Kilgore of the Washington Post provided a summary of the entire situation last November:

"Harper, the No. 1 overall selection in the 2010 draft, reached an oral agreement on his current deal less than a minute before the Aug. 16 midnight deadline to sign picks. The five-year major league contract, rare for a draftee, called for Harper to be paid $9.9 million, including a signing bonus of $6.25 million. However, the Nationals insisted that the contract not contain a clause that would allow Harper to opt out of the contract terms and into baseball's lucrative salary arbitration system once he was eligible; Harper's agent, Scott Boras, was equally adamant that the virtually standard opt-out clause be included."

When the Nationals presented Harper with the completed written contract a few days later, Boras and Harper's family refused to sign it because Washington omitted the opt-out clause. As a result, the MLB and the players association jumped in to provide a compromise for the two sides, which ultimately set up a future grievance hearing to determine if an opt out clause was necessary if Harper were to qualify for salary arbitration.

Harper is now considered a "Super Two" arbitration player because he's accrued enough service time (between two and three years) and ranks within the top 22% of all two-year players. He was called up at the end of April in 2012 and logged All-Star campaigns in 2012 and 2013 and won the NL Rookie of the Year in 2012. Being that he wasn't on the Opening Day roster in 2012, Harper has not yet spent three full seasons at the MLB level, which is required of players seeking arbitration. The "Super Two" status provides the exception for Harper and other accomplished players deserving a salary increase.

The 22-year-old will make $1 million in 2015, but if he's arbitration-eligible, he'll receive a big salary bump. For example, FOX Sports' Ken Rosenthal notes that Kansas City Royals' first baseman Eric Hosmer was the top hitter in the 2014 "Super Two" class and was able to land a $3.6 million salary, up from the $528,500 he earned in 2013. Hosmer's raise was nearly seven times his 2013 salary, which means Harper could end up being costly for the Nationals.

For the team's financial interests, it's probably best they fight the opt-out clause in the grievance hearing. However, it may affect their future relationship with Harper.