FOXBOROUGH, Mass. -- Relaying a random act of kindness by New England Patriots defensive end Derek Rivers also sparked thoughts of how his presence on the field might affect the team's pass rush in 2018. Rivers, whose recovery from a torn ACL last August is progressing and has him on target for the 2018 season, set Youngstown State's school record with 41 career sacks.

One of the Patriots' goals this offseason has been to add more depth in this area.

In 2016, the four-man rotation of Chris Long, Jabaal Sheard, Rob Ninkovich and Trey Flowers was effective, and having four quality players kept everyone fresh with a good rotation. The Patriots didn't have that in 2017, but they are taking steps to correct matters.

Here is the breakdown of edge players:

Flowers (6-foot-2, 265): He led the team with 6.5 sacks in the 2017 regular season and also led the way by playing 75.6 percent of the defensive snaps (a total that would have been higher had he not missed two games due to injury). Flowers enters the last year of his contract and is in position to land a considerable increase from his $1.907 million base salary.

Deatrich Wise Jr. (6-5, 271): The 2017 fourth-round draft choice from Arkansas had a productive rookie campaign (26 tackles, five sacks) and could be primed to contribute even more. Wise played 51.3 percent of the defensive snaps in the regular season, but he missed time in the preseason with a concussion and also sustained a concussion in the postseason. That injury history bears watching in 2018.

Adrian Clayborn (6-3, 280): The seven-year veteran was the team's biggest free-agent signing this offseason, inking a two-year deal with a base value of $10 million. That's a significant investment and reflects the market for midlevel pass-rushers. Clayborn had a career-high 9.5 sacks last season with Atlanta, although six of them came in one game against overmatched Cowboys backups. He has mostly played on the right side.

Rivers (6-5, 250): The team's top draft pick in 2017, who was selected in the third round (No. 83 overall), seemed to be coming on last preseason before tearing his ACL in a mid-August joint practice with the Texans. He should factor into substitution packages as a pass-rusher, and with the Patriots in sub about 90 percent of the time last season, that could mean a significant role. Rivers' fit in the base defense will also be interesting to watch, as he might be more outside linebacker than pure defensive end.

Eric Lee (6-3, 260): Claimed on waivers last November, he stepped in and played 26.5 percent of the defensive snaps, totaling 19 tackles and 3.5 sacks. Lee, who entered the NFL as an undrafted free agent out of South Florida in 2016, has experience playing outside linebacker in a 3-4 scheme in Houston, and defensive end in a 4-3 scheme in Buffalo.

Harvey Langi (6-2, 252): The 2017 undrafted free agent out of Brigham Young made the 53-man roster out of training camp last year, and one thing that stood out from his play was physicality. He also showed a variety of pass rush moves in training camp. A car accident in which he and his wife sustained significant injuries ended his season after he played in just one game, but he should be on target to be ready for the 2018 offseason.

Geneo Grissom (6-4, 265): A valuable special-teams player through his first three seasons, as well as a quality locker room presence, he hasn't emerged on defense.

Keionta Davis (6-4, 260): Signed as an undrafted free agent out of Chattanooga, he spent last season on the reserve/non-football injury list. He is currently viewed as a long shot, but after totaling 10.5 sacks and three forced fumbles in his senior season of college -- and also faring well against a high level of competition in facing Alabama -- his presence on the depth chart shouldn't be dismissed.

Dont'a Hightower (6-3, 265): The six-year veteran and captain on defense might fit best in the middle, playing off the line, but his flexibility to move to the edge in different packages is also valuable. In terms of the pass rush, when Hightower is coming downhill on an A-gap blitz, there aren't too many players in the NFL who are tougher to block. He is lower on this "edge" list because of the projection he will return to more of an off-the-line role in 2018 after missing half of last season with a torn pectoral muscle, but he's still part of the pass rush and does end up on the edge at times.

Kyle Van Noy (6-3, 243): A hybrid player who has played off the line of scrimmage and lined up on the edge in an outside linebacker-type role, his versatility is one of his best assets. Van Noy had 5.5 sacks last season and was an effective blitzer up the middle, so he belongs in any discussion about the pass rush.