Wisconsin will face an interesting offseason forthcoming.

Attrition within college football programs from year to year is always constant. That includes players exhausting their eligibility, declaring early for the NFL Draft, or simply moving on from respective teams via transfer portal or giving up playing at this level.

That holds true for the Badgers as they head into 2021. But with the option of an extra year of eligibility, this has the potential to be an intriguing few months of not just who develops at critical positions but who returns to Paul Chryst's team.

Let BadgerBlitz.com note that all players are worth watching during the offseason at their particular groups -- but based on athletes' announcements about coming back or not, along with 2020's results -- here are five key positions we will hone in on heading into 2021.

Quarterback is the position that is most talked about by those outside the program. At Wisconsin, how Graham Mertz improves from year one to year two as a starter will be a storyline for the offense and the team.

BadgerBlitz.com has stated these stats previously, but Jack Coan completed 60.2% of his throws for 515 yards (average of 103 yards through the air) with five touchdowns and three interceptions during the 2018 season where he played in five games (with four starts).

A year later in 2019, Coan improved to connect on 69.6% of his passes for 2,727 yards and 18 touchdowns in his first full season as a starter. The then-junior only threw five interceptions in 14 contests.

Mertz ended his redshirt freshman year completing 61.1% of his throws for 1,238 yards with nine touchdown passes to five interceptions. He rebounded from a tough stretch to hit on 11 of 17 passes for 130 yards with one score through the air in the Dec. 30 victory over Wake Forest in the Duke's Mayo Bowl. Just what is next in his evolution as a Wisconsin signal caller?

Speaking of Coan, the position group will also be without him for 2021. The New York native emerged as one of the leaders of the team in the past couple of years, but he will now head to Notre Dame.

Chase Wolf stepped in for meaningful playing time during the final two games, finishing the year completing six of eight throws for 29 yards with one touchdown. However, he also threw two interceptions in key times that could have been costly.

Danny Vanden Boom, walk-on Daniel Wright and 2021 signee Deacon Hill will round out Jon Budmayr's room.

Opportunities could certainly arise for a few players in this group. True freshman Jalen Berger appears to be the next big back for Wisconsin, finishing as the team's leading rusher (301 yards, five yards per carry, two touchdowns). Though he was not used much in the passing game during his first year, he could be a viable threat out of the backfield going forward. This offseason will be a big opportunity for growth if all goes according to schedule during this COVID-19 pandemic.

Garrett Groshek would provide a nice complement in the backfield if he decides to return to the program for a sixth year. He has not officially confirmed whether or not he will come back for 2021, however, and John Settle's room could be low in numbers in terms of in-game carries if the former walk-on moves on.

Nakia Watson decided to enter the transfer portal. That could leave room for Isaac Guerendo and/or Julius Davis to work their way into receiving more carries. Do Brady Schipper and three incoming true freshmen make a splash? Based on the Dec. 29 tweet from Inside USC's Scott Wolf, are the Badgers in the transfer market portal for former Trojan Markese Stepp?

Development is key for all positions, but the one most arguably to keep an eye for UW heading into 2021 is the wide receiver room.

Wisconsin showcased dynamic offensive output against Illinois and Michigan with a healthy combination of senior starters Danny Davis and Kendric Pryor -- both in receiving against the Illini and rushing the ball against the Wolverines. Then the two missed a combined nine contests (Davis sat out the final five contests, Pryor missed four) and the duo caught just 11 receptions. The passing game was not the same.

Jack Dunn -- who led the receivers in receptions and was second on the team overall with 28 -- and true freshman Chimere Dike (12 catches, 189 yards, one touchdown) stepped up the most out of that position group, but more will be needed to challenge opposing defenses. Devin Chandler flashed some ability with a couple receptions against Iowa, along with an 18-yard reverse against Wake Forest. Can he, A.J. Abbott, Taj Mustapha, Stephan Bracey and Isaac Smith make the strides to fill out depth?

Pryor announced his return for 2021 already, but we still have not heard anything official about Davis's status and whether he takes advantage of another year of eligibility. Same with Dunn, who told reporters on Dec. 22 that he was "leaning towards coming back" but had not made a "definitive decision" at that time.

Class of 2021 signees Skyler Bell and Markus Allen will not enroll early. Can the two incoming freshmen find a way to break into reps?

This unit is key in being the first line of defense against opponents' run games, and when you have injuries or lack of experience in this room, it affects the success of Jim Leonhard's unit overall (see: 2018 where UW allowed over 155 rushing yards per game).

First and foremost, the position group will need to find a new assistant, according to reports first by The Athletic's Bruce Feldman and later the Wisconsin State Journal's Colten Bartholomew.

Nose tackle should not necessarily be a worry, as the two-deep of Keeanu Benton and Bryson Williams will be in good hands. However, the defensive end group will also see at least one player gone with Isaiahh Loudermilk publicly declaring his goodbye earlier this week. Garrett Rand, another fifth-year senior, announced on Jan. 9 that he would leave the game of football altogether "due to numerous injuries and their potential long-term impact."

Redshirt junior Matt Henningsen was lost for the year early on due to a left arm injury, but the program tweeted in December his plans of pursuing his masters in electrical engineering and returning to the team. Isaiah Mullens played in all seven games for Wisconsin and will be elevated up to a more prominent role. A relatively inexperienced group resides after the aforementioned players. Establishing depth here will be key with Boyd Dietzen (who did not play in 2020, according to UW's participation logs), Rodas Johnson, Gio Paez, James Thompson Jr. and Cade McDonald.

BadgerBlitz.com confirmed with UW earlier this week that Mike Jarvis, Wisconsin's lone 2021 signee for the defensive line, is slated to enroll early for the program.

Joe Rudolph's group holds talented players, but how he sets up his top five before the season opener against Penn State on Sept. 4 will be interesting to watch.

Cole Van Lanen confirmed that he will not return to Wisconsin for 2021 in a social media post on Friday. Logan Brown stepped up during the Duke's Mayo Bowl in place of Jon Dietzen, who started in place of Van Lanen at left tackle the final two games of last season. Will Brown, the former four-star recruit in the 2019 class, lock up the left edge of the line in his third year in the program?

The right side of the line appears to be in good hands with Tyler Beach and Logan Bruss at tackle and guard, respectively. The latter also has played tackle often during his UW career, and when he was out against Wake Forest, redshirt sophomore Michael Furtney started at the spot.

Furthermore, the cross-training set forth on the interior should set Wisconsin in a place for at least contributors to develop and provide versatility. Josh Seltzner played in six of seven games in 2020, starting three at left guard, and the former walk-on will provide a veteran presence. There are others like Joe Tippmann, who could also provide options at multiple positions on the interior.

At center, Kayden Lyles suffered a season-ending injury against Indiana, but Cormac Sampson (with a sprinkle of true freshman Tanor Bortolini against the Hoosiers and Iowa Hawkeyes) took over duties towards the end of the year.

*Cornerback: There are players with experience in the defensive backfield. Faion Hicks returns, but who else earns reps with Rachad Wildgoose declaring for the 2021 NFL Draft? Caesar Williams also stated last month that he "wouldn't entirely say I've committed to a decision yet."

*Outside linebacker: There is talent in Bobby April's room, but who will develop into more of a pass-rushing threat? Nick Herbig certainly could fit the bill there, and Aaron Witt flashed during the Duke's Mayo Bowl with two tackles for loss that included a strip-sack in the fourth quarter. Does Noah Burks return, and how will Izayah Green-May return after a season-ending injury?

*Fullback: Mason Stokke is off to chase the dream of the NFL, according to a tweet by agent Kevin Gold. John Chenal has proven to be effective running and blocking, but does Quan Easterling also see more playing now?

Ed. note, Jan. 10: Updated defensive line section to include Rand's decision to leave the game of football.