Packers position preview: Defensive line

GREEN BAY, Wis. -- Between now and the Green Bay Packers' first training camp practice on Saturday, we will break down each position group.

Next up is the defensive line.

Returning players: Mike Daniels, Datone Jones, B.J. Raji, Josh Boyd, Jerel Worthy.

Gone from last season: Johnny Jolly, Ryan Pickett, C.J. Wilson.

New this season: Khyri Thornton (third-round pick), Letroy Guion (street free agent), Mike Pennel (undrafted rookie), Carlos Gray (undrafted rookie), Luther Robinson (undrafted rookie).

Position coach: Mike Trgovac (seventh season).

Biggest issue: The Packers picked Jones in the first round of the 2013 draft to be an every-down player. Last season, he could not even show he was effective on third down as a pass rusher, let alone play in the base defense. Nevertheless, defensive coordinator Dom Capers has big plans for Jones this season. He will feature Jones and Daniels as his two primary inside pass rushers in the nickel defensive package and hope that Jones makes the same kind of second-year improvement that Daniels did last season, when posted 6.5 sacks and just two as a rookie in 2011.

Player to watch: As a rookie last season, Boyd had trouble just getting on the field early in the season. The fifth-round pick was inactive for the first five games and six of the first eight. But by season's end, he was playing more than Jones. Over the last six games (including playoffs), he played more than twice as many snaps (102) as Jones (60) and could have an even larger role this season.

Medical report: Worthy, a second-round pick in 2012, has missed as many games as he has played in. He blew out his knee in the regular-season finale of his rookie year and then played in only two games last season after coming off the physically unable to perform list on Nov. 23. But his problems may not be behind him. He did not take part in any of the offseason practices, and it's unknown whether he will be ready for the start of camp.

Help wanted: Deciding not to re-sign Jolly, Pickett and Wilson was a sign the Packers wanted to get younger (and perhaps smaller and quicker) up front. But they still need to find some run-stopping defensive linemen. Re-signing Raji and moving him back to his old nose tackle position could help. Perhaps Guion (6-4, 315), who played the last six years for the Vikings, or Thornton (6-3, 304) also could help against the run. When Pickett and Jolly were playing at their best early in the season, the Packers had a top-five run defense before it tumbled to 25th.

Quotable: "You're always going to invest in your defensive line," Trgovac said. "But obviously we didn't get to where we want to be last year. And we didn't finish the way we wanted to finish, so obviously there's some improvement to be made."

Previous installments

July 14: Quarterbacks

July 15: Running backs

July 16: Receivers

July 17: Tight ends

July 18: Offensive line