The Red Sox and Yankees are suddenly and surprisingly engaged in a game of roster brinksmanship over the fate of Pawtucket outfielder Chris Carter, who is as shocked as anybody to be involved and trying to find a way out of it so he can play in September for the New York Mets.

Carter was one of two players to be named later in the Tuesday deal that sent Mets reliever Billy Wagner to Boston. Because the trade was made after July 31, all players have to clear waivers to play again this season. But the New York Yankees put in a waiver claim to block Carter's move to the Mets, presumably to create roster difficulty for the Red Sox.

Having pulled Carter back from waivers, the Red Sox must now carry him on their 40-man roster for the rest of the season –– a spot they might prefer to use on a pitcher. The trade can't be completed until after the season, denying Carter a chance to play and the Mets a chance to see what they've got in him.

The Sox and Mets are now trying to develop their own strategies to find their way out of the mess, and get Carter to the Mets by Sept. 1.

Carter himself is perplexed to suddenly be a pawn in the middle of Yankees-Red Sox roster gamesmanship. He was hoping this was his chance to show a big-league team what he could do in an extended callup, but now he's locked in limbo.

It's been a trying season for Carter. The 1B/OF made his major league debut last season for Boston, and started the year on the Red Sox active roster, but he sent down to Pawtucket after only five at-bats. The 26-year-old former Stanford star has had a decent, but not spectacular, year as one of the few offensive bright spots on a dismal Triple-A team.

He expected that he'd get a chance to show the Mets what he could do in September, but now he's left to wonder if he'll even make it onto the Red Sox active roster.

The situation mirrors the case of minor-leaguer Adam Stern in 2006, when Boston's Stern was the player to be named later in a deal that exchanged him for Baltimore's Javy Lopez. The Tampa Bay Rays put in a claim to block the transaction, forcing Stern to wait until the offseason to join Baltimore.

dbarbari@projo.com