Who could be the Lions' goodbye guys?

In the wake of a 12-loss season, with 23 unrestricted free agents and ongoing salary-cap issues, the Detroit Lions roster could look considerably different before they hit training camp next summer. The easiest way to start making changes is to not re-sign some of those free agents. That's seemingly inevitable, especially if players such as Cliff Avril, Justin Durant and DeAndre Levy receive generous offers from another team. But what about some of the current starters who are signed for next season? Would the Lions consider going in a different direction to trim their salaries? Here are five core players whose futures will be interesting to monitor this offseason: 1. Right guard Stephen Peterman: Considered the weak link on the offensive line, Peterman arguably is the unit's worst pass blocker. General manager Martin Mayhew stressed that some of quarterback Matthew Stafford's troubles in 2012 were created by interior pressure. Reading between the lines, that would suggest that Peterman was the main culprit because left guard Rob Sims and, to a lesser degree, center Dominic Raiola graded out as better pass blockers. Peterman has a cap hit of more than 3 million for the final year of his contract. He has started every game the last three seasons, but will he be back for another? Possible replacements for him currently on the roster include 2012 first-round draft pick Riley Reiff, who apparently can play tackle or guard, and Bill Nagy, who was on the injured list all season following ankle surgery. 2. Defensive end Kyle Vanden Bosch: KVB's production took a noticeable nosedive at age 34, in his 13th NFL season. He went from eight sacks in 2011 to 3 12 in 2012, from four forced fumbles to zero and from one fumble recovery to zero. The pass rush needed to be dominant to try to hide a suspect secondary, but it was a major disappointment because the defensive ends didn't deliver. Vanden Bosch reportedly will have a cap hit of nearly 11 million in the final year of a deal that he signed when he came to Detroit from Tennessee as a free agent in 2010. It's a tough spot for the Lions. Vanden Bosch was an important part of the transformation that led the team to the playoffs in 2011. His leadership and work ethic were invaluable during that turnaround. But this is a cutthroat business. If he's not capable of playing to a higher level than he showed in 2012, would the Lions seriously consider parting ways? 3. Offensive tackle Jeff Backus: He finally missed a game in his 12th season, sitting out Thanksgiving Day because of a hamstring injury. Backus returned the next week and finished out the season. He still hasn't addressed his future plans, if he might retire or whether he definitely wants to come back for at least another year. He has one year left on his contract with a cap hit around 3.5 million. Mayhew said he met with Backus shortly after the season but that they didn't discuss retirement at all. "Jeff and I got here at the same time," Mayhew said. "I thought we needed to talk. It was a good conversation about where we are as a team, as an organization. I kind of got his viewpoint on it. He's a pro, been around a long time. I have great respect for him." The Lions drafted Backus' likely heir apparent last April. Reiff seems ready for a full-time role. It could be left tackle if Backus retires or it could be elsewhere on the line if Backus returns. 4. Raiola: Often the target of ridicule among fans, he also would be entering his 13th season with the Lions. Raiola, 34, who started all but four games over the last 11 years, has made it clear he doesn't plan to retire just yet. His deal has a cap hit of more than 6 million. Although he's still a decent pass protector, the Lions seriously need to upgrade their run blocking to develop more of a balanced offense. Despite public opinion, there are some potential downsides to consider before assuming the Lions automatically would be better off without Raiola. Like Vanden Bosch, Raiola provides veteran leadership, an intangible that the club is otherwise sorely lacking. Raiola's experience calling out signals in the middle of the line also could be missed, at least short term, because continuity on the O-line is so important. 5. Receiver Nate Burleson: There was speculation, even Burleson acknowledged it, that he could be the odd-man out in 2013 after the Lions took a receiver in the second round each of the last two years in the NFL Draft. But Titus Young turned into a head case and Ryan Broyles suffered another knee injury, both of which increased Burleson's value. Still, at age 31, he's coming back from surgery for a broken leg that forced him to miss the final 10 games. What's more, he has two years remaining on a contract that has a cap hit around 6.5 million in 2013. Burleson has indicated he will rework his contract to help the team financially. "I had a talk with Nate," Mayhew said. "He wants to finish his career here. The doctors feel good about where he is. That's a decision we'll make down the road, I think."