The Mets have struck a naming-rights deal with Citigroup for their new stadium, according to a person familiar with the situation, and the new ballpark -- set to open in 2009 -- will be called CitiField. The new name will be announced Monday, when the Mets hold a ceremonial groundbreaking at Shea Stadium, which is scheduled to close its doors in the fall of 2008. The new stadium, being built next to Shea, will rise in what is now a parking area. "It's weak because it's commercialization of a landmark," Mike Afromowitz, 30, of Manhattan, said of the new name. "I grew up as a fan liking the Mets, and for them to change it would be kind of a slap in the face."