ESPN NFL Insider Matt Williamson, a former college and pro scout for the Cleveland Browns, was gracious enough to provide his perspective on the San Diego Chargers roster overall, along with how the team can address specific areas of needs.

Although the Chargers snuck into the playoffs for the first time since 2009 last season, Williamson is not impressed with the overall talent and depth on San Diego's roster.

"They have a lot of areas of need," Williamson said. "They're talent deficient throughout the roster. The schedule helped them last year. I thought Mike McCoy or Bill Belichick should have been voted the coach of the year last year. They got the most out of their roster."

Williamson said he liked the scheme change on offense by McCoy and former offensive coordinator Ken Whisenhunt, emphasizing Philip Rivers getting the ball out quick, and the Chargers' reliance on the run game.

"I think they are very well coached," Williamson said. "And that goes a long way. But sometimes Guy A has to beat Guy B across from them, and they don't have a lot of guys that can do that."

Williamson also believes the Chargers benefited from a soft schedule. That won't be the case in 2014, with the AFC West playing the NFC West.

"I think the AFC was so putrid, that wasn't a playoff-caliber team," Williamson said. "Don't me wrong, they won games and got hot at the right time. But all of those teams that were fringe playoff teams in the AFC, none were quality options. None of them had a chance to contend for a title. I thought the Cardinals were way better than the Chargers, or any other fringe playoff team in the AFC.

"They have a 6-10 kind of roster. But they did win games."

With the help of Williamson, we take a closer look at San Diego's top five positions of need: interior offensive line, receiver, defensive tackle, outside linebacker and cornerback. We start with interior offensive line first.

Chargers O-line depth: Projected starters -- LT King Dunlap, LG Chad Rinehart, C Nick Hardwick, RG Jeromey Clary, RT D.J. Fluker. Reserves -- T Mike Harris, G Johnnie Troutman, T Willie Smith, T Kenny Wiggins, T Nick Becton, C Nick McDonald.

What's your evaluation of San Diego's talent level at offensive line?

Williamson: "I don't see any Pro Bowlers. Fluker's the best of the bunch. He's a good run blocker, and played well at right tackle for a rookie. If you move him to guard he would be a Pro Bowler. You can run behind him.

"Dunlap is good. I thought he would be a stop gap guy. His play was surprising. Starting left tackles in the NFL don't grow on trees, and he's a starting left tackle. Rinehart is solid at left guard. Hardwick and Clary are concerns. I don't see any young guys riffling up depth chart."

Williamson sees Clary and Troutman as backups or swing guys on the interior offensive line, and not long-term starters at right guard.

What do they need to accomplish this offseason to improve?

Williamson: "I would draft some sort of interior offensive lineman that can play center and guard pretty high. They need somebody there with upside.

"I definitely think the whole was much greater than the sum of the parts. And to me that lends itself to coaching. They have proven that they can get by with some deficiencies, but just imagine if they didn't have to?"

One player the Chargers could consider in the first two rounds is UCLA offensive lineman Xavier Su'a-Filo. Chargers offensive line coach Joe D'Alessandris worked Su'a-Filo out at his pro day.

He measured in at just over 6-foot-4 and 308 pounds at the scouting combine, so Su'a-Filo has decent size. He played left tackle his freshman season, and switched to guard for his final two seasons with the Bruins, so he brings versatility.

Su'a-Filo has played in zone and man blocking schemes -- the Chargers run a mix of both. Su'a-Filo is agile for his size, able to get out and pull around the edge in the run game.