Matt Williamson is a former scout for the Cleveland Browns, and spent the last 10 years at ESPN as a scout and co-host of the podcast "Football Today."

Players are changing uniforms right now at a rapid pace, and, on the surface, it's easy to get excited about your favorite team's newest addition via free agency. But, as we all know, many moves this time of year don't pay off.

Here are four players who might not work out well with their new teams:

Matt Kalil, Panthers

Kalil was the fourth overall pick in the 2012 draft, and was considered such a good player and prospect at USC that he manned the left tackle position for the Trojans, relegating Tyron Smith, maybe the best offensive lineman in the NFL right now, to right tackle.

He now joins his brother in Carolina, and while that sounds touching, the fact is he just hasn't played well at all for some time now for the Vikings. Injuries have certainly contributed to that lack of success, and he has played with bad knees for much of his career, but that doesn't exactly make him someone you'd want to pay big money.

There's no doubt the Panthers needed an upgrade at left tackle, and the options were limited, but it could be argued that Kalil, whose best season came during his rookie year, and who's coming off hip surgery, really isn't much of an upgrade over Michael Oher. That isn't saying much. The payoff could be big, but the Panthers gave Kalil $27 million guaranteed and $55 million over five years, which is high-end money for even a top-10 left tackle.

Considering the money Russell Okung got from the Chargers, he fits this mold as well, and is yet another illustration of offensive linemen, especially tackles, getting overpaid in today's NFL.

Malcolm Smith, 49ers

We all remember Smith as the Seahawks' Super Bowl MVP, but that's the only really noteworthy thing he can put on his professional resume.

Sure, the 49ers have more cap space than they know what to do with, but to give a below-average starting linebacker $13 million guaranteed is ludicrous. San Francisco would have been much better off giving that money to Gerald Hodges and keeping him in a 49ers uniform.

Not only does Smith fail to make impact plays, he also misses far too many tackles and is a liability in coverage, as well as offering very little as a pass-rusher. This move makes very little sense.

Kenny Stills, Dolphins

Stills isn't changing teams like the other players on this list, but will he live up to what Miami expects him to be?

This isn't to imply he's a bad player, and clearly the Dolphins have a great understanding of who he is as a person and player. Even though he has played four years in the league, two in Miami and two in New Orleans, Stills is only 25 years old, and is coming off a very successful season in his first year in Adam Gase's offense.

However, it can't be forgotten that the Saints shipped him out just two years ago for very little return. Again, Stills is a good player, but just don't expect him to keep up the pace he set last year with the Dolphins, with whom he scored nine touchdowns on just 42 receptions. Stills was also targeted 81 times, so he only caught about half of the balls thrown his way, although many of his targets certainly came deep downfield.

His $20 million guaranteed is just too much compensation for what Stills brings to an offense. It feels like the Dolphins are buying at the peak of his value, which rarely ends well in the NFL free-agent market.

Robert Woods, Rams

Woods isn't a bad player, and the Rams certainly need receiver help for Jared Goff. And yes, free-agent wide receivers are making big money on the open market nowadays. But the fact is, at his very best, Woods is a possession receiver that blocks well and moves the chains.

At his best, he's an average No. 2 wide receiver, and again, that might be being kind. Hopefully the Rams don't see him as anything more, but giving him $39 million over five years with $15 million guaranteed indicates otherwise.

Over his four seasons in the NFL, Woods has always racked up between 552 and 699 yards, and has a dozen receiving touchdowns in his career. These numbers are a pretty good indicator of who he is as a player.