After a 2020 season that allowed players to transfer with instant eligibility, sit out a season, and return for another, it's hard to keep track of who all will be playing this season in the Big Ten Conference. More importantly, who will be putting on the most impressive performances?

We continue our annual Ranking the Big Ten series today with the cornerbacks.

Rankings: QB | RB | WR | TE | OG | OT | C | DE | DT | OLB | ILB

Indiana cornerback Tiawan Mullen is the top returning cornerback in the Big Ten. He had the most sacks (4) of all the Big Ten cornerbacks in 2020 and second-most interceptions (3) of the returning cornerbacks from 2020. He is right behind his teammate Jaylin Williams who had four interceptions last season.

Mullen was named a 2020 first-team All-American by FWAA and Phil Steele after his sophomore season. He had 22 tackles, one force fumble, five pass breakups, and those three interceptions and four sacks.

As for his PFF grades, the first-team All-Big Ten selection by media had the third-highest pass-rush grade with an 88.8 and the fourth-highest run defense grade with an 80.7. Mullen's total defense score ranked No. 7 in the Big Ten cornerbacks (80.7).

Mullen has been Indiana's starting cornerback since week seven during his freshman season in 2019, and the 5-foot-10, 180-pound back hasn't let up since. Get used to seeing the name Tiawan Mullen because it will be all over the Big Ten this season and potentially the NFL the following season.

Nebraska cornerback Cam Taylor-Britt doesn't have in-your-face stats. However, a closer look shows he hasn't played to his full potential yet.

The 2020 second-team All-Big Ten selection by conference coaches had the second-highest run defense grade with an 82.6, off of No. 1 by 0.2. The rest of his PFF grades aren't as high. Taylor-Britt scored in the upper to mid-60s in total defense, pass rush, and coverage. His tackling grade was 54.6 in 2020.

One of Taylor-Britt's best performances was against Penn State, covering the second-best returning wide receiver in the Big Ten, Jahan Dotson. Taylor-Britt held Dotson to two catches and 27 yards. Dotson averaged over 120 yards per game before meeting Nebraska and Taylor-Britt.

Taylor-Britt held all of his receivers to under 40 yards except for Purdue's David Bell, who capitalized on a rare mistake with an 89-yard reception during his 132 receiving yard game.

Taylor-Britt will have more opportunities to shut down some of the best wide receivers in the Big Ten, and he has proven time and time again that he is up for the task.

After missing most of Penn State's 2020 season due to injuries, Tariq Castro-Fields decided to come back in 2021 for a proper senior season. After all the work he has put in, Castro-Fields deserves it.

Despite only playing three games, Castro-Fields was voted an All-Big Ten honorable mention by the coaches and media. In 2020, the 6-0, 200-pound cornerback has nine tackles, four stops, and one pass breakup in 177 snaps.

In the 2019 season, Castro-Fields's PFF grades were almost all in the low 60s. Last season, his defense grade improved from 62.7 to 67.2, and his tackle grade jumped from 46.8 to 62.7.

If Castro-Fields is fully healthy in the fall, which he should be, he'll have a chance to finish what he started in 2017 and do it the right way.

Ohio State cornerback Sevyn Banks leaped right into starting in the Big Ten for the conference champions. He played 170 snaps in 2019, then 483 snaps in 2020. Being one of the starting cornerbacks for the Buckeyes comes with a lot of responsibility. Banks found this out in 2020.

The 2020 All-Big Ten honorable mention recorded 22 tackles, two stops, one interception, and six pass breakups last season.

The 6-foot-1, 200-pound cornerback scored in the mid to upper-50s in PFF's total defense, run defense, pass rush, and coverage grades. His tackle grade was the highest at 70.7, which ranks him No. 33 in the category.

Banks had four games where he scored less than 30 points in any of the grades. If he can eliminate those meager numbers and create more consistency on a game-to-game basis, Banks will make a massive improvement come fall.

Last by certainly not least on this list is Iowa veteran cornerback Matt Hankins. The fifth-year player has 28 starts for the Hawkeyes dating back to the final two games of his freshman year in 2017.

Hankins had 34 tackles, 11 stops, one interception, and four pass breakups in eight games in 2020. The previous season in 2019, he had 46 tackles, one sack, two interceptions, and six pass breakups.

Like several of the players in this series, Hankins PFF grades dropped from 2019 to 2020. Most likely, the consequences of fewer games and more chaos. His tackling grade took the biggest hit (pun intended) as it fell from 84.6 to 70. The others all decreased an average of eight points.

Hankins is capable of scoring higher in his PFF grade and his tackles, interceptions, and pass breakups. During his last season with Iowa, he'll probably do just that.