The Patriots' secondary is looking like a shell of the version many expected to see in 2021.

Going into the season, it looked like depth in the defensive backfield could eventually be a problem. They were a team that was going to utilize a lot of "big nickel," or three-safety looks, yet their depth chart behind Devin McCourty, Adrian Phillips and Kyle Dugger was noticeably lacking.

They were a team that was going to play a lot of man-to-man coverage, yet their top cover corner Stephon Gilmore was going to begin the season on the physically unable to perform list, and the list of names behind Gilmore and fellow projected starters J.C. Jackson and Jonathan Jones wasn't all that inspiring. 

Now almost halfway through the year the Patriots are wafer-thin, particularly at corner.

Gilmore and the Patriots couldn't find common ground with his contract so he was traded to the Panthers. And Jones suffered a season-ending shoulder injury.

Cassel: Ranking Jones, Herbert among top 10 QBs drafted since 2018

That has left Jalen Mills -- signed in the offseason as a jack-of-all-trades -- as the team's No. 2 corner behind Jackson. Without Jones in the slot, the Patriots turned to practice-squad callup Myles Bryant versus the Jets in Week 7. As depth, the Patriots have Joejuan Williams, who was benched and made a healthy scratch in Week 6 after a lackluster showing against the Texans in Week 5. They also have rookie Shaun Wade, who was back at practice Wednesday after missing time with a concussion, as well as special-teams ace Justin Bethel.

If the Patriots want to dip into their practice squad for help, they just added veterans Brian Poole and De'Vante Bausby. Poole has spent five seasons in the league, primarily as a slot defender for the Falcons and Jets. Bausby has been more of a boundary player in his time with the Bears, Eagles, Broncos and Cardinals.

Maybe the Patriots can piece together their secondary with practice-squad elevations. Maybe Wade, a fifth-round pick of the Ravens traded at the end of camp, can be more than a developmental option. Maybe Williams will live up to his draft status for the first time since being selected in the second round in 2019.

But that's more "maybes" than the Patriots would likely want to deal with -- particularly as a team that wants to play as much man-to-man coverage as they have over the last several years under Bill Belichick. At some point, they may have to acknowledge a talent influx is necessary to persist in that fashion.

Is a talent influx an option?

Good corners are hard to come by. For teams that have them, they typically aren't available via trade. But the NFL's trade deadline is less than a week away, and it's not all that difficult to peg potential sellers. Win or lose this weekend against the Chargers, the Patriots should not be selling. (We get into why on this week's Patriots Talk Podcast...)

Patriots Talk Podcast: Patriots ID in focus and why trading Stephon Gilmore still makes sense | Listen & Subscribe | Watch on YouTube

Here are a few potential deals for defensive backs that could help the Patriots make a run ...

Patriots acquire: CB Kyle Fuller

Broncos acquire: 2022 fourth-round pick

When Kyle Fuller, 29, was signed to a one-year deal by the Broncos this offseason, which was followed by drafting Alabama corner Patrick Surtain II in the first round, they looked like one of the deepest secondaries in football. Now, Fuller is riding the bench. He's ranked as Pro Football Focus' 126th corner among players with at least 100 snaps. On a base salary of $9 million. That can't last. Maybe a change in scenery is enough to get him into a better frame of mind and back to what the Broncos thought he'd be.

Primarily an outside-the-numbers option, acquiring Fuller would likely bump Mills into the slot on a more regular basis. If it happened, the Patriots (less than $3 million in cap space) would have to create some room to be able to absorb the remaining portion of Fuller's base salary -- unless the Broncos were willing to eat some of that dough. The cost here might be prohibitive as the Patriots aren't going to want to part with valuable picks. But the competition for Fuller could be real, upping the price.

Patriots acquire: CB Joe Haden

Steelers acquire: 2022 sixth-round pick

Haden, 32, is a little older than Fuller. But he's less expensive (Patriots would be responsible for just under $4 million of his base salary), and he's had a better year. He checks in with PFF's 64th best grade in coverage. He's another outside-the-numbers option, and he's a veteran. He's coming from a system, though, that plays more zone than the Patriots do.

Like Fuller, Haden will be a free agent after the season, and the Steelers probably aren't going anywhere in a difficult AFC North behind aging Ben Roethlisberger. Haden should be available. And as a rental, it shouldn't cost much in terms of compensation.

Patriots acquire: DB Desmond King

Texans acquire: 2022 sixth-round pick

Younger and cheaper than either of the other two names mentioned above, King, 27, has seemed like a Patriots fit since before he entered the league. The former Iowa Hawkeye was featured prominently in our Prototypical Patriots series back in 2017 because of his instincts to play the football (14 picks in three years), his elusiveness as a return man on special teams, and his agility (third-best three-cone time among defensive backs at the combine). He was a First-Team All-Pro defensive back and a Second-Team All-Pro returner for the Chargers in 2018. But he's bounced around the league a bit. He was traded to the Titans for a sixth-round pick last season. Then became a free agent and signed with Houston.

If the Patriots can swing a deal with Nick Caserio and get the 2018 version of King to play in the slot? That would qualify as a steal. He's been a disappointment this season, allowing a rating of 123.6 when targeted.

Patriots acquire: CB Vernon Hargreaves, 2022 seventh-round pick

Texans acquire: 2022 sixth-round pick

If Caserio isn't willing to bite on a deal to give the Patriots a slot defender, would he entertain a move that would send a boundary corner to New England? Hargreaves has been relegated to a reserve role -- he played just eight snaps last week -- after starting four games this season. Like the others mentioned above, he's in a contract year, and the Patriots have more than enough cap space to absorb what remains of the 2016 first-rounder's contract.

Hargreaves has struggled in a bad secondary in Houston, and he has more experience as a zone corner than a man-to-man guy. But if the Patriots are looking to hit on a low-cost gamble, they could do worse.

Patriots acquire: CB Avonte Maddox

Eagles acquire: OLB Chase Winovich

The Patriots love (love) acquiring joint-practice opponents. This would be an opportunity for them to continue that amazing streak as well as upgrade in the slot. Maddox has performed as one of the better slot players in the league this year. He has PFF's 8th-best coverage grade in 2021, and he's allowing a quarterback rating of just 74.4 when targeted. But Maddox, like everyone else on this list, is in a contract year.

At 2-5, the Eagles are likely going nowhere fast -- though their division after the Cowboys is a mess -- and they should be focused on building for the future. Can Winovich be part of that future? Perhaps. Philadelphia is going to need pass-rushers of "all shapes and sizes," according to PhillyVoice.com's Jimmy Kempski, and general manager Howie Roseman may be intrigued by Winovich's potential.

With a regular workload in 2020, Winovich finished with PFF's 21st-best pass-rush productivity score. He's currently on injured reserve, but he has a year left on his contract. Though he's been a valuable member of the kicking game in New England this season, defensively he's buried behind Matt Judon, Kyle Van Noy, Josh Uche, Dont'a Hightower, Deatrich Wise and Jamie Collins as potential edge rushers.

The team also just drafted edge rusher Ronnie Perkins in the third round back in the spring.