The team stated to the Daily News that Howard is in the market for new representation and has not yet informed the club who his new agent will be.
Howard is eligible for arbitration after the 2007 season. The slugger made $355,000 in 2006, when he led the Majors with 58 homers and 149 RBIs.
"He's obviously due for a big raise," assistant general manager Ruben Amaro Jr. told the newspaper.
Howard is the biggest name in a crew of talented young Phillies eligible to file for arbitration next month, including pitcher Brett Myers, second baseman Chase Utley, relievers Geoff Geary and Ryan Madson and center fielder Aaron Rowand.
On Sunday, Leon Rose, who represents NBA stars Allen Iverson and LeBron James, denied reports that he is Howard's new agent.
While it would be an honor to represent a player of Ryan Howard's magnitude in any sport, I have not spoken to Ryan nor do I represent him," Rose told FOXSports.com.