Since his rough first 30 days after injury return, he seems to hae performed o.k., but he still is in AA and turns 26 this fall.
Is there any value in promoting him to AAA and call him up when rosters expand under a "sink or swim" mentality to see what they have moving forward?
Havens has not played since last Thursday while dealing with a stiff back.
I can't speak for the "organization," with respect to Havens. I can speak for myself. The former first-round pick is hitting .234/.366/.374 overall with 13 doubles, nine homers, 56 walks and 97 strikeouts in 84 games in AA as a 25 year-old. Sure, the walks are nice, but the 28% strikeout rate for a player who is old for AAA is a monster-sized red flag. On its face, that just does not deserve a big league look. Lets look deeper.
Kevin is right however, that Havens has been better in the last two and a half months. In his first 27 games in April and May he hit a punchless .153/.318/.235. Since June 1, in his last 57 games, he's hit a much more productive .269/.388/.433. His extra-base hit rate is up, but even in his "good" period, he's fanned at a 28% rate and run a .368 batting average on balls in play. That won't work in the big leagues.
As far as "sink or swim" for Havens now, I just do not see a point. Sure, he's on the 40-man roster already, so they would not need to make a roster move to add him. The team will not learn that much more about him in four weeks of big league games and there is no point in taking away playing time from Daniel Murphy to play a guy two years younger, who might never be as good as Murphy.
Believe it or not, Murphys has actually been an above average offensive performer at second base. His .296/.339/.419 line with 33 doubles is good enough for a 108 wRC+, good enough for eighth among all MLB second basemen. wRC+ adjusts for ballpark and 100 is league average. Sure, there are holes in Murphy's game. He gives away some of that value defensively, he doesn't walk much (6.1% of the time) and he does not hit the ball over the wall (four HR in 2012). On the other hand, he makes lots of good contact as his 12% strikeout proves.
You could argue that this is the peak of the 27-year old Murphy's value. That could well be true, but Havens is not a better player now, and the odds are not particularly strong that he'll ever be a better big leaguer hitter and overall second baseman than Murphy.
The 2012 Mets have had many problems, and the front office will have to work very hard to avoid a very similar set of issues on the 2013 Mets. Second base is not particularly high on the list. Murphy is no star, but he's a capable enough Major League player. Transferring a September's worth of playing time from Murphy to Havens does neither player nor the Mets any short-term or long-term gain.