With the NFL's free-agent frenzy beginning to wind down, it's a good time to take a look at where the Bills have bulked up their roster so far this offseason -- and where they've thinned out.

Here is a snapshot of what positions I would rank as having the most and least depth on the Bills' roster, which provides an updated look at what areas the Bills could target in the draft:

Razor thin:

Dolphins tight end Charles Clay caught 58 passes for 605 yards during the 2014 season. Steve Mitchell/USA TODAY Sports

Tight end -- As Bills fans continue to wait with bated breath for the team to submit an offer sheet for free-agent tight end Charles Clay, who was assigned the transition tag by the Miami Dolphins, the Bills are down to bare bones at this position. Even if the Bills land Clay, they'll need to address this spot with one of their early picks in the draft. Chris Gragg and MarQueis Gray are nothing more than depth-level players, but that's all the Bills have at the moment.

Could use some help:

Offensive line -- It's not as much an issue of quantity here than it is quality. The Bills could fill out an opening-day roster easily with the personnel they have along their line. But is Chris Williams the best option to start at left guard? Will Seantrel Henderson take the necessary step forward to become a viable, long-term NFL starter? Will Eric Wood and Cordy Glenn bounce back from down seasons? How will Richie Incognito fare after a season-and-a-half away from the game? Will Cyrus Kouandjio show any promise? The questions are endless.

Off-the-line linebacker -- This was one of the Bills' deepest positions a month ago, but trading away Kiko Alonso (in a fair deal that upgraded their offense) has made it a need. There's no issue with Preston Brown and Nigel Bradham as the starters in the base defense, but if either goes down with an injury, Ty Powell is the next man up. He has proven to be a valuable special teams piece over the past two seasons, but he barely has seen time on defense.

Safety -- This is a repeat of last offseason, when the Bills let Jairus Byrd sign a monster deal with the New Orleans Saints. That worked out for Buffalo, as Da'Norris Searcy stepped into a full-time role and flourished. Will Duke Williams or Bacarri Rambo be able to do the same? Or should the Bills try to add another player to the mix here?

No worries:

Defensive line: The Bills re-signed Jarius Wynn and have Stefan Charles to compete for a starting role at defensive end. It won't be the strongest position on the Bills' roster -- which is why I considered putting this in the "could use some help" category -- but I don't see the Bills devoting more resources to this spot. Marcell Dareus and Kyle Williams are top-flight options at the other two defensive line positions.

Wide receiver: He might have been a luxury, but signing Percy Harvin reduced the need to add another receiver. Like last summer, the battle for the last spot at this position will be fierce. I wouldn't consider Marquise Goodwin a lock.

Quarterback: OK, so "no worries" probably isn't the best way to describe the Bills' quarterback situation. But it's already a three-horse race for the starting spot. There isn't room for anyone else.

Running back: Between LeSean McCoy, Fred Jackson, Bryce Brown and Anthony Dixon, the Bills are set here. How the No. 2 spot between Jackson and Brown shakes out will be a top training camp story line.

Defensive end/outside linebacker: It's unclear what Jerry Hughes' exact role will be, but at the very least he'll be a rusher opposite Mario Williams in sub packages. If he starts in the base defense at Sam linebacker over Manny Lawson, there will be sufficient depth at that spot.

Cornerback: The Bills have been plenty deep at this position since they added Corey Graham and Ross Cockrell last offseason. Top cornerback Stephon Gilmore enters the final year of his deal, but that's a situation that might not be addressed until later this year.