Chicago Bears position preview: Bears need OLB Pernell McPhee to pressure the QB

The Chicago Bears begin training camp July 30 on the campus of Olivet Nazarene University in Bourbonnais, Illinois.

Leading up to the first practice, we'll breakdown the roster, position by position. We next move to the linebackers; a position group that underwent a massive offseason overhaul.

The cast: Pernell McPhee (5th season), Christian Jones (2nd season), Jared Allen (12th season), Sam Acho (5th season), Mason Foster (5th season), Lamarr Houston (6th season), Willie Young (6th season), Jon Bostic (3rd season), DeDe Lattimore (2nd season), Shea McClellin (4th season), John Timu (1st season), Kyle Woestmann (1st season), Jonathan Anderson (1st season), David Bass (3rd season).

Key number: McPhee signed a five-year, $38.750 million contract with $15.5 million guaranteed.

For starters: McPhee, 26, is Chicago's best linebacker. The outside linebacker had 7.5 sacks, 21 quarterback hits and 64 pressures last season for the Baltimore Ravens. The Bears feel good about second-year inside linebacker Christian Jones, who ranked third in tackles (98) in 2014. The other inside linebacker spot is up for grabs between a host of players, including Foster and McClellin. McClellin enters camp on the bubble. Acho played 3-4 OLB for the Arizona Cardinals, and may have a leg up on the trio of ex-4-3 defensive ends moving to linebacker: Allen, Houston and Young. Allen is looking to revitalize his career after posting only 5.5 sacks last year. Houston and Young missed the entire offseason program rehabbing from injuries.

Backup plan: The Bears' leading tackler from one year ago, Bostic, remains in the conversation but failed to participate in organized team activities because of a back problem. Bostic is behind. He's put up decent numbers the past two years, but makes critical mistakes on occasion. Bass is a player to watch. He showed some flashes at 4-3 defensive end the past two seasons, but may be a more natural fit at outside linebacker. Lattimore had five special teams tackles in 2014.

Next: Secondary