According to the Mets, Jenrry Mejia has a posterior cuff strain and will return to throwing when his pain subsides.
Judging by what occurred with Sammy Gervacio earlier in the year with the Astros, we can probably expect Mejia to miss in the range of 2-3 weeks. My guess is a month and possibly even more, though. According to this site, healing can take up to three months.
Gervacio was placed on the DL on April 7th with the same exact injury and then activated 17 days later. He went on to re-aggravate that injury a week or so later. After being optioned to Triple-A a few days after that, Gervacio made a handful of appearances with Round Rock before being placed on the DL after his May 16th appearance. He's still on the DL today. What doesn't help, though, is that Gervacio has one of the most unorthodox deliveries in baseball, so that has to have made it worse.
Basically, the injury is not a major one should the Mets proceed with caution and bring him back only after he's completely healthy. I doubt, though, that any team will trade for him until he proves he's healthy and that's not likely to happen before the trade deadline.
Mejia Update
