It's early to form too many hard opinions about fantasy defenses, with the rest of free agency and of course the NFL Draft still to come. But with most of the big names having either been released or signed on, or both, we can identify a few early risers and fallers, both obvious and not so much.

Denver. The Broncos quickly locked up the free agent market's top pass rusher in DeMarcus Ware and top cornerback (arguably) in Aqib Talib. Will his meeting with new teammate Wes Welker be awkward after that playoff collision? Denver ranked 13th in sacks last season and seems certain to be better with Ware across from Von Miller (who missed much of last year). Talib is better than Rodgers-Cromartie, who won't be back. Seemingly further helping Denver is that division foes Kansas City and Oakland saw their offensive lines gutted the first day of free agency.

New Orleans. A year ago the Saints ranked 4th in sacks but 29th in takeaways. Now they've added Jarius Byrd, who with Buffalo the last five seasons recorded 22 interceptions and forced 11 fumbles. Good NFL player and even better fantasy player in IDP leagues, and he should add some opportunism to New Orleans' defense.

Chicago. The Bears' defense was horrible last season, but they've quietly made a couple of nice additions. Defensive end Lamarr Houston from Oakland was one of the best (young) players at his position available, and former Lion Willie Young has some pass rush potential. The Bears aren't done yet, either -- it'd be nice to see them bring back as-yet unsigned defensive tackle Henry Melton.

Jacksonville. Let's be clear: as we said before free agency kicked off, the Jaguars had nowhere to go but up. They've ranked last or next to last in sacks in four of the last five seasons. Still, they did have 11 more sacks last year (31) than they had in 2012 (20), and now they've added linemen Red Bryant and Chris Clemons from Seattle, re-signed Jason Babin, and also added Ziggy Hood from Pittsburgh. Babin and Clemons have pass rush ability, Bryant is a run-stuffer, and Hood -- though he didn't pan out in Pittsburgh -- has potential, if defensive-minded head coach Gus Bradley can get it out of him. We won't call Jacksonville a top-20 fantasy defense just yet, but they're doing some nice things to address a problem area.

On the other side of the coin, several teams look worse.

Dallas. What can you say? Ware's contract forced the cap-strapped Cowboys to release him, but he was one of the few good things they had going. They're also apparently parting ways with Jason Hatcher (11 sacks last year) and Anthony Spencer on their defensive line, replacing them so far with players who disappointed elsewhere last year -- Jeremy Mincey and Terrell McClain. Dallas already had secondary problems, and a gutted pass rush won't help hide their issues there.

Cleveland. The Browns replaced D'Qwell Jackson with Karlos Dansby and T.J. Ward with Donte Whitner. Older, but not better for a defense that disappointed last season.

Oakland. Hate to pick on the Raiders, and really, what they've done (or failed to do) on offense is a much greater concern. But they let Lamarr Houston, one of their best defensive players, depart, and thus far are trying to fill the void with Justin Tuck, whose best football with the Giants came back in 2010 -- before a late-season surge down the stretch last year, a contract push by the 30-year-old that apparently didn't fool the Giants. Oakland's offense looks scary bad, but its defensive depth chart is equally alarming, and they've done little to address it. Oakland actually had a top-20 fantasy defense a year ago, but don't expect that to happen again.

--Andy Richardson