NFL's Best Surprise Offseason Additions Through Week 5

Every NFL offseason is highlighted by the free-agency period, in which a bevy of veteran players change teams either by signing or via trade.

While the blockbuster moves—like, say Ndamukong Suh to the Miami Dolphins—grab headlines, sometimes the under-the-radar acquisitions end up having the biggest impact.

Everyone took notice when the Philadelphia Eagles handed running back DeMarco Murray a five-year, $40 million free-agent contract, for example. Yet, less-heralded free-agent back Ryan Mathews has outproduced him so far.

Few probably expected Mathews to be the shining back in Philly in the early 2015 season, just like few probably expected Brandon Marshall to have a revival with the New York Jets or Josh McCown to shred defenses like a Pro Bowler with the Cleveland Browns. 

Of course, the unexpected is what makes the NFL so darn fun.

Here are the offseason additions who have been the biggest surprises so far. 

Tyrod Taylor, QB, Buffalo Bills

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After quarterback Kyle Orton announced his retirement following the 2014 season, it was fair to wonder just how much the quarterback position would be an issue for the Buffalo Bills in 2015. None of the three quarterbacks who entered the offseason competition—EJ Manuel, Matt Cassel and Tyrod Taylor—really seemed to be the answer.

However, Taylor, a four-year backup with the Baltimore Ravens, played well enough in the preseason to win the starting job and has continued his strong play in the regular season.

The one-time Virginia Tech standout has completed 70.1 percent of his passes, has racked up 1,097 passing yards and 187 rushing yards and has produced 11 touchdowns with just four turnovers. His passer rating of 103.6 ranks seventh in the NFL among starting quarterbacks.

More importantly, he has the Bills sitting at 3-2 and appearing dangerous on the offensive side of the football. The team is ninth in scoring offense, with an average of 24.8 points per game. 

Costing just $3.35 million over three years, Taylor is looking like quite the steal. 

Unfortunately, his surprisingly hot start has hit a pothole. According to Jeremy Bergman of NFL.com, Taylor has suffered an MCL injury and is going to have to sit for at least a week.

Per Bergman, the Bills plan to start Manuel, a former first-round pick of the franchise, in Week 6 against the Cincinnati Bengals. 

*UPDATE: On Wednesday, Matthew Fairburn of Syracuse.com reported that Taylor took "some" first-team reps in practice and will leave his playing status up to the coaching staff. 

If Taylor does get the start, one would assume that his mobility and rushing ability would be limited by the knee injury. 

Stevie Johnson, WR, San Diego Chargers

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Speaking of Buffalo, do you remember when the Bills had a bright young star named Stevie Johnson who looked like he might be the next big thing at wide receiver? Well, that was a couple of years ago, and Johnson had since slipped into obscurity—first with a bad quarterback situation in Buffalo and later in the run-oriented San Francisco 49ers offense.

This is why the San Diego Chargers' signing of Johnson was a fairly under-the-radar move.

He wasn't available for Monday night's game against the Pittsburgh Steelers because of a hamstring injury, but through the first four weeks of the season, he has looked very much like the same pass-catcher who was putting up 1,000-yard seasons in Buffalo.

In four games (three starts), Johnson has produced 18 receptions for 205 yards and two touchdowns. This puts him on pace for roughly 770 yards and seven touchdowns, assuming he doesn't miss any more games. This would make for his best season since 2012.

The key for San Diego is that Johnson isn't expected to be a No. 1 target. With guys such as Keenan Allen, Malcom Floyd and Antonio Gates on the roster, Johnson is more of a complementary piece. The fact that he is a complementary piece that seems to have developed chemistry with his quarterback makes him one of the more valuable additions of the offseason.

Johnson spoke to the Chargers' official website about his developing chemistry with quarterback Philip Rivers during the offseason:

"

We kind of get that feel.  And it kind of took me by surprise because I haven’t seen stuff like that.  The passes that he’s thrown and we’ve completed, it’s like, I’m in the middle of the play and looking like (wow), he put that ball there. I’ll go up and get it. That is a part of the game.  Just playing and trying to make plays.

"

Rivers probably is the best quarterback Johnson has ever played with in his career, and the receiver is beginning to look like one of the best third or fourth options Rivers has ever been able to target. 

Malcolm Smith, LB, Oakland Raiders

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Former Super Bowl MVPs don't typically make for underrated additions, but linebacker Malcolm Smith's move from the Seattle Seahawks to the Oakland Raiders definitely wasn't one of the bigger stories of the offseason. 

Of course, it's not like Smith was regularly a game-changer in 2014. He started just five games, made just 38 tackles and defended a single pass. He also failed to log a sack. This is probably why the Raiders were able to land him with an underwhelming two-year, $7 million deal.

So far, it seems like the Raiders are getting much more than their money's worth.

Smith has already matched his start total from 2014 and has surpassed his numbers in tackles, sacks and passes defended. Through five weeks, he has racked up 40 tackles, two sacks, two passes defended and one forced fumble.

Having former Seahawks linebackers coach Ken Norton Jr. as his defensive coordinator has definitely helped Smith thrive in his new home. However, it seems that the linebacker has benefited just as much from finally landing a starting role.

Smith appears to be on pace for a Pro Bowl season. This is likely what the Raiders were hoping for when they signed him, but it's probably not what a lot of people were expecting. 

Ryan Mathews, RB, Philadelphia Eagles

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We'll be honest here: Eagles running back Ryan Mathews hasn't exactly been setting the football world on fire. Through five weeks, he has produced just 205 yards on the ground to go with two touchdowns. That's good but certainly not great.

The surprise here is that Mathews has outperformed teammate DeMarco Murray in a number of categories. Mathews has more yards (205 vs. 130) and is averaging 5.0 yards per carry to Murray's 2.7 yards per carry.

Mathews has also been healthier and has appeared in one more game than his more expensive counterpart. 

To be fair, neither back has been particularly impressive in Philadelphia, probably because of a subpar offensive line—the Eagles are rated 18th in run blocking by Pro Football Focus. However, Mathews is clearly taking better advantage of his opportunities. 

Few expected that a guy who continuously disappointed with the Chargers would step in and outperform the reigning NFL rushing leader. The fact that Mathews' contract pays him $4.3 million less per season than Murray, on average, is one of the reasons why Murray made last week's opening-month bust list. 

Brandon Marshall, WR, New York Jets

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Brandon Marshall has been one of the league's better receivers for several years now, so he certainly isn't the biggest surprise on this list. However, few expected he would put up near-career numbers with the New York Jets.

For starters, the Jets haven't been known for stellar quarterback play in recent years. Also, Marshall was coming off a season in which he played just 13 games and produced just 61 receptions and 721 yards. Those were the lowest reception and yardage totals of his career since his rookie season in 2006.

Yet, Marshall has been spectacular in New York, thanks in large part to some surprisingly strong play from journeyman quarterback Ryan Fitzpatrick (though not surprising enough to put The Beard on our list). 

Marshall has racked up 30 receptions, 400 yards and three touchdowns. If this pace continues, he'll have a 120-catch, 1,600-yard, 12-touchdown season.

Not too shabby for a guy the Jets acquired with a fifth-round draft pick. 

Dion Lewis, RB, New England Patriots

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New England Patriots running back Dion Lewis is probably the biggest surprise on this list for one major reason—prior to this season, he hadn't seen a regular-season snap since 2012.

Now he just might be one of the most exciting running backs in football. Through four games, he has amassed 180 yards rushing, 238 yards receiving and three touchdowns. He is currently rated ninth overall among running backs by Pro Football Focus.

Lewis has been so good in the early 2015 season that the Patriots were willing to grant him a two-year, $2.6 million extension just three games into the season. 

The Patriots aren't the first team to have their eye on Lewis, of course. He started his career with the Philadelphia Eagles, who later traded him to the Browns. 

"Dion is a back who runs with very good quickness and vision," then-Browns coach Rob Chudzinski said after the trade, per Mary Kay Cabot of the Northeast Ohio Media Group. "He is a promising young player who will add depth, which is extremely important at that position."

Unfortunately, Lewis suffered a fractured fibula during the 2013 preseason with Cleveland and couldn't stick with the Indianapolis Colts a year later. (I bet they wish they'd reconsidered that move.)

The Patriots were obviously willing to give Lewis a chance, and the gamble seems to be paying off in a big and surprising way.

Jabaal Sheard, DE, New England Patriots

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The Patriots have a recent history of milking big-time production out of relative unknowns, so it shouldn't be too surprising to see a couple of New England players on this list. 

Though he isn't quite as much of an unknown as Lewis is, defensive end Jabaal Sheard has still been surprisingly good through four games. The Patriots signed him to a two-year, $11 million deal to bolster the defense as a situational pass-rusher. So far, so good for the former Browns linebacker.

Sheard, a second-round pick in 2011, was converted to outside linebacker after two years with the Browns—a move that fit him about as well a mustache fits Pharrell Williams.

Now that he is back at the defensive end position, Sheard is again looking like he could emerge as an elite pass-rusher. He has already logged four sacks to go with 11 tackles. According to Pro Football Focus, he has also produced two quarterback hits and 14 total hurries. 

Pro Football Focus ranks Sheard sixth overall among 4-3 defensive ends in pass-rush efficiency. 

He wasn't a complete sleeper signing, of course, but after he produced just 7.5 sacks over the past two years, his current pace is a welcome surprise. He's on pace for a 16-sack season, which would easily be the best of his pro career.

At $5.5 million per season, he's a good bargain. 

Chris Johnson, RB, Arizona Cardinals

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Running back Chris Johnson was one of the later additions of the 2015 offseason, but that hasn't stopped him from being one of the league's more pleasant surprises.

The Arizona Cardinals signed Johnson in mid-August when rookie running back David Johnson was dealing with a hamstring injury. Johnson ended up making the team and then earning a starting role when Andre Ellington suffered a Week 1 knee injury.

The end result has Johnson looking like one of the biggest running back steals of the offseason.

John Gambadoro of ArizonaSports.com recently explained:

"

Because Johnson was victimized in a drive-by shooting that the left the driver of the vehicle he was in dead, a lot of teams passed on him. Now five weeks into the season, the team that bided its time and played the waiting game came out on top. Johnson has been by far the best running back acquisition in the NFL this season and he is a big reason why the Arizona Cardinals are 4-1 and all alone in first place in the NFC West.

"

Likely because of the events of Johnson's offseason, the Cardinals were able to snag the veteran rusher with a prove-it deal worth just $870,000 in base salary. In return, the Cardinals have received a starting-caliber running back who could realistically be in line for a Pro Bowl nod.

Johnson has made four starts in five weeks and has already rushed for 405 yards and two touchdowns. He is averaging a solid 5.1 yards per carry, which is his best average since his 2,000-yard season of 2009. 

Johnson is on pace to gain roughly 1,300 yards and six scores this season. More importantly, he has found a way to bring some balance to the offense of the 4-1 Cardinals. 

Josh McCown, QB, Cleveland Browns

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If Dion Lewis is the biggest surprise on our list for being away from football for two seasons, Browns quarterback Josh McCown is probably the second-biggest surprise because he is now in his 13th season.

For the better part of those seasons, McCown has been nothing more than an average-at-best backup. Few people (OK, no one) likely thought that he would be a top-10 quarterback five weeks into the 2015 season.

Yet, this is exactly what McCown is, at least in terms of passer rating. His rating of 102.8 is eighth in the league among starting quarterbacks. 

McCown suffered a concussion on the opening drive of the season and missed the rest of Week 1 and all of Week 2. However, he has returned with the type of offensive potency the Browns haven't had at the quarterback position—well, in some ways, ever.

The journeyman signal-caller has set new franchise records since returning from his concussion. He has passed for 1,154 yards since returning—a team record for a three-game stretch. He also has become the first quarterback in Browns history to have three consecutive 300-yard games. The 457 yards passing he had on Sunday against the Ravens is also a team regular-season game record. 

According to Andie Hagemann of NFL.com, McCown is also now the only player in league history to have more than 450 passing yards, two passing touchdowns and a rushing touchdown with no turnovers in a single game. 

Saying that McCown has outperformed Cleveland's expectations might be the understatement of the NFL year to date.