J.J. Putz is progressing toward a return but he isn't close yet. With Putz having struggled before his injury and Heath Bell thriving in the closer role it's certainly possible that Putz will be brought back in a set-up capacity.
Hanley Ramirez has some hamstring issues but he may just miss a few more games instead of being placed on the DL again.
Cory Luebke is having some elbow issues and it's possible he won't return this season. He's probably worth dropping unless you don't have anyone else to place in your DL slot.
Matt Harvey left today's game with a back issue but it's unknown at this point whether it's a serious injury or not.
Logan Morrison and Mike Stanton will each come off the DL early next week. Stanton will likely play right-field while Morrison will play first base. Morrison should hit in the middle of the order and should have solid fantasy value for those in need of some power and RBI.
Michael Cuddyer will miss at least a few games with a rib or oblique injury. He could be placed on the DL if he doesn't improve soon enough.
Adam Eaton is restarting his rehab and could be back in about 3 weeks if all goes well.
Daniel Hudson will need another Tommy John surgery and will miss the rest of the season.
Johnny Cueto re-injured himself and was placed on the DL. He will likely miss at least 3 weeks.
Gerrit Cole will make his MLB debut Tuesday night vs. the Giants. Cole has huge upside and is a must-add in NL-only leagues. In mixed leagues you should add him if you need SP help but I wouldn't drop an established solid starter for him.
Zack Wheeler will likely be called up 5 days after his next AAA start to make his debut with the Mets. He's a must-add in all leagues and should be picked up right now unless your league is really shallow. I like him more than Cole and think he can make a big impact much like Matt Harvey did last season.
Tyler Colvin was called up by the Rockies and I really like his power-bat at Coors Field. If you have daily transactions and lineups and can make sure he's playing on a particular day then I suggest adding him.
Tony Cingrani will be called up to start Tuesday vs. the Cubs and replace Johnny Cueto in the rotation for at least the next few weeks. I really like Cingrani and think he's worth a pickup in just about any league because of his elite strikeout potential.