Five under-the-radar free agents who could help out the Patriots

Cornerback Rock Ya-Sin played for the Raiders last season after three years with the Colts.Peter Aiken/Associated Press

The Patriots have made some decent-sized splashes into the free agency pool over the last 10 days, upgrading at several need spots, including offensive tackle, tight end, receiver, and running back.

They also made a concerted effort to keep many of their internal free agents in town, especially on defense, which has been a strength for most of the last two seasons.

Major movement will come next month when the draft kicks off, but there are some under-the-radar moves that can still be pulled off and cause ripples in the water during the second and third waves of free agency.

Here are five guys who can either plug right into the starting lineup or provide valuable depth heading into OTAs and minicamp.

▪ CB Rock Ya-Sin

Probably the most high-profile (and coolest) name on the list, the 26-year-old is a solid cover guy and could immediately fill a need on the boundary, especially if Jalen Mills does indeed shift to safety.

Ya-Sin has the size (6 feet, 192 pounds) and speed to match up with perimeter receivers. He possesses the strength to play press-man coverage and the range to excel in zone schemes.

Though not a true ballhawk (two interceptions in four seasons), Ya-Sin stays on his opponent’s hip and closes fast.

A one-year deal (they’re very popular this season) makes sense here.

▪ DT Poona Ford

A run-stuffing widebody, the 5-11, 311-pounder looks like a prototypical nose tackle but moves like a ballerina. Ford, 27, is deceptively light on his feet, shifts gears smoothly, and has a high-running motor (what else would you expect from a Ford?)

Could Poona Ford fit in Foxborough?Ted S. Warren/Associated Press

The Patriots have nice depth along the interior, but adding Ford (on a team-friendly pact) could transform this unit from good to elite.

▪ WR D.J. Chark

He may not have Odell Beckham Jr.’s résumé, but he has a bunch of highlight-reel catches that are hard to ignore.

Chark, 26, has exceptional length and good speed, and at 6-4, he is a crazy-tough matchup along the sideline, particularly when it comes to 50-50 balls.

Pairing Chark with DeVante Parker outside (with JuJu Smith-Schuster and Mike Gesicki inside) would be a dream scenario for Mac Jones and could create nightmares for defenses.

▪ LB/DE Trey Flowers

The most familiar name of this bunch, Flowers had his best days in New England when he collected 164 tackles and 21 sacks in his first four seasons (2015-18).

Flowers, 29, has struggled with injuries over the last four seasons with Detroit and Miami, but if he can stay healthy, the 6-2, 245-pounder could provide a nice niche option as a matchup piece along the front seven.

In his best days, Flowers was used on the edge, where his speed and strength would often catch tackles by surprise and leave them flat-footed in their backpedal. He also would be employed on the interior, where his quickness and ability to squeeze through gaps would frustrate centers and guards and infuriate quarterbacks.

Could Trey Flowers enjoy a second act with the Patriots?Barry Chin

If the Patriots can get Flowers back on track in a familiar system, he could pay huge dividends for comparatively short money.

▪ QB Jeff Driskel

A strong-armed veteran, and a onetime Red Sox draftee as a pitcher, Driskel doesn’t have a ton of game experience but he has a lot of NFL experience.

With five seasons (and four organizations) under his belt, he can be a sounding board and voice of reason for Jones and Bailey Zappe. A younger, cheaper Brian Hoyer, if you will.