It's impossible to predict with perfect accuracy which units on the Cleveland Browns will thrive and which will fail in 2012. But past performances and recent trends can provide enough data to give it a good shot. So here are three areas of strength and three areas of concern as the Browns complete preparations for their season opener against the visiting Eagles:

Potential areas of strength:

  • Offensive line: Granted, if rookie right tackle Mitchell Schwartz struggles, the unit might fall on the opposite side of the ledger. The Browns already boast one of the better left sides, including Pro Bowlers in tackle Joe Thomas and center Alex Mack. Left guard Jason Pinkston is potentially strong as well. But the jury is still out on right guard Shawn Lauvao and Schwartz, who is at this point a far superior run blocker than pass protector.
  • Running backs: Rookie Trent Richardson hasn't taken an NFL game snap -- not even in the preseason. So let's just call this a hunch. He displayed downright scary athleticism early in camp. Coupled with a first-string offensive line that consistently opened up holes in the three exhibition games in which it played, there is certainly justifiable optimism. In addition, backup Brandon Jackson enjoyed a fine preseason.
  • Defensive line: When second-year tackle Phil Taylor (pectoral surgery) returns at midseason or a bit earlier, this unit should be fine. Fellow tackle Ahtyba Rubin has quietly emerged as one of the better and certainly most mobile linemen in the league, and end Jabaal Sheard could reach double figures in sacks. The combination of free agent run stopper Frostee Rucker and pass rusher Juqua Parker at the other end spot provides talent and depth.

Potential areas of weakness:

  • Linebacker: The loss of underrated weakside linebacker Chris Gocong (Achilles surgery) for the season devastated a unit that already lacks speed, depth and talent. Veteran replacement Kaluka Maiava might be fine against the run, but he cannot match the pass-rushing ability of Gocong. The strength here is middle linebacker D'Qwell Jackson, but he also is stronger against the run. Strongside linebacker Scott Fujita completes a starting trio that is aging and slow.
  • Wide receiver: This is the great unknown, but a giant leap forward would only result in mediocrity. The additions of supplemental pick Josh Gordon and fourth-rounder Travis Benjamin brings badly needed speed and athleticism, but also inexperience. Gordon is already the most talented receiver on the roster, but it will be up to second-year wideout Greg Little to grow into a 1,000-yard threat for the Browns to feel comfortable. Of course, all will be lost if rookie quarterback Brandon Weeden can't find them.
  • Secondary: Youth will be served here, particularly if fear becomes reality and cornerback Sheldon Brown proves he can no longer cover the fleet receivers of the NFL. The Browns will help him out high and low, but only a strong pass rush will save him from being exposed. This unit can thrive if cornerback Joe Haden and strong safety T.J. Ward do. But the Browns are taking a chance with free safety Eric Hagg, unproven veterans such as Dimitri Patterson and Usama Young, and a bunch of kids as backups.

Stay dialed in on the Cleveland Browns on Twitter at @CBSSportsNFLCLE throughout the season with on-site updates from CBSSports.com RapidReports correspondent Marty Gitlin.