Philadelphia, PA (Sports Network) - The NFL's free-agent period began four weeks ago, and nearly all of the impact players have signed contracts by now.

With the draft still a couple of weeks away, let's take a look at teams that were the biggest winners and losers so far in free agency.

WINNERS

Tampa Bay Buccaneers: When a team enters the free-agent period reportedly more than $60 million under the NFL salary cap, it's easy to attract top players with big contracts and signing bonuses. It's not such a great accomplishment that Tampa Bay was able to outspend teams for top talent, but the Bucs were able to zero in on a couple of needs and significantly improve their team.

Former Chargers wide receiver Vincent Jackson has come aboard as the Bucs' new No. 1 receiver. While Mike Williams was disappointing as last year's No. 1 receiver, he is likely to be one of the league's better No. 2 guys this season. Along with tight end Kellen Winslow Jr., they will give quarterback Josh Freeman an excellent group of targets.

With the signing of ex-Saints guard Carl Nicks, Tampa Bay now boasts three Pro Bowl players on its offensive line (Davin Joseph and Donald Penn are the others). That should help bolster a running game that took a step back last year. If Tampa Bay drafts Alabama running back Trent Richardson, which is certainly a possibility, this could quickly become one of the league's most explosive offenses.

With legal problems making cornerback Aqib Talib's future cloudy, Tampa Bay signed ex-Lions corner Eric Wright and also re-signed Ronde Barber. If the Bucs don't draft Richardson, their likely first-round target would be LSU cornerback Morris Claiborne, who could benefit from a year of Barber's tutelage before becoming the Bucs' No. 1 corner for years to come.

On Saturday, Tampa Bay made another shrewd signing, adding Amobi Okoye to their defensive tackle rotation for one year, $2 million. He's only 24 and has upside.

Denver Broncos: OK, this ranking is based almost exclusively on the addition of one player. However, that player - Peyton Manning - might be enough to turn an 8-8 Broncos team into one of the AFC's top contenders.

Sure, there are injury risks in signing Manning, who has had four neck surgeries and hasn't played since a Jan. 8, 2011 playoff loss to the New York Jets. If he's healthy enough to play, though, the expectation is that he'd represent an enormous upgrade over Tim Tebow. Sure, the Broncos are unlikely to repeat their No. 1 NFL rank in rushing, but they might double their passing output. Manning also makes the players around him better. If Demaryius Thomas and Eric Decker looked like promising receivers with Tebow throwing to them, just watch what they'll do with Manning throwing passes their way.

Manning loves to use his tight ends, and the Broncos also added an old friend in ex-Colt Jacob Tamme and former Texan Joel Dreessen to fortify that position. Tracy Porter, the former Saints cornerback, was a great value signing at one year for $4 million.

Buffalo Bills: Talk about turning a weakness into a strength. The Bills had extreme difficulty putting pressure on opposing quarterbacks last season, finishing with just 29 sacks. If you don't count their one aberration - a 10- sack game against the Redskins - the Bills had just 19 combined sacks in their other 15 games.

New defensive coordinator Dave Wannstedt has decided to switch the Bills from a 3-4 to a 4-3 defense, intensifying the search for two new defensive ends with pass rushing skills. Enter Mario Williams, whom the Bills have rewarded with the richest contract ever given to a defensive player. If he can stay healthy, Williams would be a lock for double-digit sacks. Last year, no Bills player managed more than 5.5 sacks.

A few days after the Williams signing, Buffalo also added former Patriots defensive end Mark Anderson, who registered 10 sacks last season. Adding those bookends - as well as re-signing top receiver Stevie Johnson - will enable the Bills to concentrate on other areas (such as left tackle, since Demetress Bell, who signed with the Eagles, will have to be replaced) in the draft.

Washington Redskins: Since big-spending Daniel Snyder has owned the team, the Redskins have often won the offseason Super Bowl. Those big-ticket signings for the most part, though, have not panned out for Washington.

This offseason should work out a lot differently than the others have for the Redskins, however. This time, instead of paying big money for former greats that are a little past their prime, Washington traded up for the No. 2 pick in the draft and will build around Heisman Trophy-winning quarterback Robert Griffin III.

The Redskins also signed a pair of young, rising wide receivers to grow with Griffin in the offense. Pierre Garcon (Colts) and Josh Morgan (49ers) are youthful and with upside, and they will bring some life to what had been a blah wide receiver group. Washington also re-signed tight end Fred Davis, so Griffin will have decent weapons at his disposal.

Washington also added some needed depth at cornerback by signing ex-Viking Cedric Griffin, and took a chance on former Pro Bowl player Brandon Meriweather to revive his career as the replacement for oft-injured LaRon Landy, who signed with the Jets.

LOSERS

Baltimore Ravens: The offseason wasn't a complete loss for the Ravens, who franchised running back Ray Rice and locked up one of the league's best young cornerbacks, Ladarius Webb, for six years. Still, a team that finished a Lee Evans drop and a Billy Cundiff hooked field goal attempt away from getting to the Super Bowl, has come away weaker in some spots.

Standout guard Ben Grubbs was lost to the Saints. Underrated linebacker Jarret Johnson signed with the Chargers. Run-stopping defensive lineman Cory Redding went to the Colts.

Baltimore could still use a left tackle, and it could stand to get younger at linebacker and in the secondary. This is going to be an important draft for the Ravens if they are to remain one of the AFC's top three teams.

Houston Texans: It's possible that the Texans would have been the AFC's Super Bowl team had Matt Schaub not been injured and forced to miss the last six regular-season games and the playoffs. Instead of taking another step forward this offseason, Houston appears to have taken a slight step back.

The Texans probably had to let Mario Williams go. They couldn't really afford to compete with the Bills' lucrative offer, and he wasn't really the best fit in Wade Phillips' 3-4 defense, anyway. But was it really necessary to send tackling machine DeMeco Ryans to the Eagles for a mere fourth-round draft pick? Was it really a great idea to cut dependable right tackle Eric Winston, who was quickly scooped up by the Chiefs? Also, cornerback Jason Allen, who was solid in 2011, signed with the Bengals.

At least the Texans locked up franchise running back Arian Foster, but they did nothing to fill their need at wide receiver, while also creating a new need at right tackle.

Miami Dolphins: The offseason began with a failed pursuit of Peyton Manning. Early on, the Dolphins also sent their best offensive weapon, wide receiver Brandon Marshall, to the Bears in exchange for just two third-round draft picks.

The quest for a quarterback netted only David Garrard, who sat out the 2011 season. The team has so far done nothing to make up for the loss of Marshall. While Miami did re-sign nose tackle Paul Soliai, he will need to make a position change as the team transitions to a 4-3 defense. Also, talented defensive end Kendall Langford was lost to the Rams, and now he'll need to be replaced.

At least Miami added former Cardinals cornerback/safety Richard Marshall to bolster a secondary that was aging.

Jeff Saukaitis is a former Sports Network writer/editor who has been a professional sports writer since 1985.

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