The work wasn't over for Lions general manager Bob Quinn and his staff when the last name was called in the seventh round of the NFL Draft last month. Quinn and Co. began working the phones before the draft was even over, trying to sign players who went undrafted.

An undrafted rookie free agent has made the Lions' opening-week roster in each of the last seven seasons.

Adairius Barnes, Cole Wick, Zach Zenner and Cornelius Lucas are guys currently on the roster who made it as undrafted rookies.

Those four names prove there is talent to be found after the draft. Here's a closer look at this year's undrafted free-agent signings:

Brandon Barnes, TE, Alabama State – Caught just 29 passes during his four-year career, but scored six touchdowns and has ideal size (6-5, 255) and good speed (4.6's).

Alex Barrett, DE, San Diego State – A tweener at 6-2, 255. Had team-highs last year in sacks (7.5) and tackles for loss (13). Named San Diego State defensive lineman of the year three times.

Dontez Ford, WR, Pitt – Missed five games due to a collar bone injury in 2016. But in 2015, when he played in all 13 games for Pitt, he averaged 19.4 yards per catch and recorded two touchdowns.

Tion Green, RB, Cincinnati – Green led the Bearcats on the ground last season with 743 yards and two scores. He rushed for more than 1,400 yards and 10 touchdowns the last two seasons combined. He's a power back, and could contribute on special teams.

Nick James, DL, Mississippi State – Played in 46 games with 15 starts and recorded 19 tackles, 3.5 tackles for loss and two sacks playing nose tackle in 2016. He's a big, strong player in the middle. He had 29 reps on the bench in the pre-draft process.

Leo Koloamatangi, OL, Hawaii – Made 20 starts in college playing all three interior line positions, which is where he projects as a professional. Was graded above average in both run and pass blocking by Pro Football Focus.

Desmond Lawrence, CB, North Carolina – Three-year starter with good size (6-1). North Carolina allowed just three passing touchdowns in 2016. Lawrence finished his career fourth in UNC history with 27 career pass breakups.

Storm Norton, T, Toledo – Massive offensive tackle who is listed at 6-foot-8, 311 pounds. He was a two-year starter at left tackle and one of the key components upfront for Toledo's high-octane offense. Two-time All-MAC selection.

Michael Rector, WR, Stanford – Rector ran a 4.42-second 40-yard dash at the Combine and finished his Cardinal career with 32 receptions for 367 yards and three touchdowns last season.

Maurice Swain Jr., DT, Auburn – A big tackle (6-5, 314) who had 22 tackles in 26 games with the Tigers. Ranked among the Top 40 JUCO prospects playing at Mississippi Gulf Coast Community College before transferring to Auburn.

Noel Thomas, WR, UConn – Led UConn in receiving with a school single-season record 100 receptions for 1,179 yards and three touchdowns. His 183 career receptions are fourth in school history.

Josh Thornton, CB, Southern Utah – Former teammate of safety Miles Killebrew. Had three interceptions and eight pass breakups last year. He's a speedster with a 4.42-second 40 recorded at his pro day.

Robert Tonyan Jr., TE, Indiana State – A former quarterback turned receiver, who is now making the switch to tight end. Caught 56 passes for 699 yards. He ran the 40 in 4.58 seconds and had a 35-inch vertical at his pro day at 6-5, 236.  

Jeremiah Valoaga, DE, UNLV – Has great size (6-6, 255) and a good skill set, but not very much experience. He also has some red flags. He was dismissed from the UNLV football program at the end of last year for violating team rules. Had 6.5 sacks the last two seasons in 14 games.