He should be traded before the non-waiver deadline to enhance the Mets' talent base in 2014 and beyond. The 35-year-old Byrd, with a contract that ends on the final day of the 2013 season, has value to the next Mets playoff team only in so far as he can return another piece of talent that will be on the roster, or even in the organization on the next day the Mets clinch. At the moment, according to Baseball Prospectus' Playoff odds, the Mets have under a 1% chance of reaching the playoffs in 2013.
Byrd, hitting .282/.325/.512 has been great for the Mets. However, the method he has used to produce these results are unsustainable. His strikeout rate is 28.3%, a career-high. His walk rate of 5.5% is a touch below his career average. His BABIP of .350 is well above his career-average of .323. His HR/FB% is 19.1%. It's never been above 10.7% for a MLB-season longer than 10 games.
He is wildly unlikely to produce as well in August and September as he has in April-July of 2013. He is even more unlikely to be as good as he has been to this point in 2013 in 2014, when he will be 36. Moreover, to have Byrd in 2014, the Mets would have to guarantee many multiples of his 2013 season. Any player under team control in 2014 and beyond, that the Mets acquire for Byrd now is a positive.
The argument for holding on to Byrd is essentially that winning in 2013 helps build for 2014. That makes sense on its face. However, winning with players in 2013 who will not be part of 2014 does not matter. The Mets made the same argument a year ago to hold on to Scott Hairston. In that case, the Mets prioritized 2012 wins over adding potentially helpful organizational pieces for 2013, 2014 and beyond. Neither Byrd nor Hairston should produce a Zack Wheeler return. However, either should bring back a live (a-ball) arm or athletic young player. Most guys do not work out, but some young pitchers turn into, oh say, Jeffrey Walters in AA. Walters has added velocity in the last few years and sharpened his slider and looks like a guy who might help the Mets' bullpen at some point in the 2014 season. Adding even that kind of player is more valuable than holding on to Byrd for the duration of the 2013 season.
Byrd is the precise kind of player, who is making relatively little money, who would be blocked in a waiver wire deal in August.