They do have one thing in common, though -- this training camp is a chance for both defensive ends to earn a bigger role for 2013.
First-round draft pick Ziggy Ansah could fill one of those spots, but the more experienced Jones and Young are competing for playing time as well.
"We've got two big guys in the middle who are wreaking havoc and causing a lot of trouble and confusion," Young said. "It's going to be critical that we set solid, strong edges, so those guys can play around in the middle."
Avril flourished at times in Detroit's defensive scheme. He had 29 sacks over the past three seasons before signing with Seattle. The Lions, meanwhile, nabbed a defensive end from the Seahawks when they signed Jones.
After 12 games with Seattle last season -- and no starts -- the 6-foot-5, 276-pound Jones returns to the Detroit area. He is from nearby Southfield and went to Eastern Michigan.
"Just coming back in and having the opportunity to start in the NFL is big anywhere," Jones said. "Playing with the guys here right now, I think the sky's the limit for us."
Jones started 28 games in the 2010 and 2011 seasons with the Tennessee Titans. He has 18 1/2 sacks in his five-year career.
Although he's never started, Young played all 16 games last season for the Lions. Now Avril and Vanden Bosch are gone, meaning he could be on the field more this year.
"That's a part of the business," Young said. "It's definitely an opportunity for myself and every defensive end."
Jones and Ansah are listed as the starters on Detroit's depth chart, with Young and Israel Idonije the top backups. Young was drafted in the seventh round in 2010.
"I think that he has skills that fit what we need from that position," coach Jim Schwartz said. "He's playing with another increase in understanding. He's a young veteran player now. He's not a young player anymore."
Ansah was taken with the fifth overall pick in this year's draft. Detroit is counting on the former Brigham Young standout to develop into a star despite limited experience. He grew up in Ghana, playing soccer and basketball, before playing football for the first time in 2010.
Schwartz told reporters not to focus too much on whether Ansah works with the starters or the backups during training camp.
"Reps are reps in camps. ... The only guys that are worried about what group people are running with are you guys," Schwartz said. "Our guys are just out there practicing and trying to get as many reps as they can and trying to do well in the reps that they get. Ziggy is no different than the other guys in that regard."
Once the season starts, Detroit's pecking order at defensive end should be a lot more clear.
"Ziggy Ansah, Idonije, Jason Jones, just take those three guys and if there was a curtain in front of them, you couldn't pick out who was who," defensive co-ordinator Gunther Cunningham said. "They are really good people. I think that runs through the defence."
NOTES: The Lions claimed LB Adrian Moten off waivers. ... S Louis Delmas (left knee) said he's preparing as if he'll play in Friday night's exhibition game against the New York Jets -- but he's not sure if he will or not.