The countdown 'til training camp is on.

In two weeks, the Browns will be back in Berea for five weeks of practices, meetings and preparations for the 2021 season — one that's filled with hype following several key additions to the defense and little changes to an offense that thrived in 2020.

We're examining each position on the roster as Day 1 of camp nears, and we're starting with a group many expect to be one of the best units in the NFL yet again in 2021.

The Running Backs
Nick Chubb
Kareem Hunt
D’Ernest Johnson
Demetric Felton
Tre Harbison
John Kelly

The Fullbacks
Andy Janovich
Johnny Stanton

What we know: One of the biggest questions the Browns faced at the beginning of last season was how they could adequately use Chubb's and Hunt's Pro Bowl talents from the same backfield. Any notion that either player wouldn't have a chance to maximize their skills was squashed as the Browns finished the season third in the NFL with 2,374 rushing yards. Chubb had 1,067 rushing yards and 12 touchdowns while Hunt provided 841 rushing yards and 11 touchdowns — five of which came as a receiver. There's zero reason to believe the duo won't have a similar, if not better output in 2021. They'll run behind the same offensive line, take hand-offs from the same quarterback and look to improve under Year 2 of head coach Kevin Stefanski's playbook, which relied on a strong run game to open big plays for the rest of the offense.

What we don't know: How much higher can the group go? Don't forget that Chubb still amassed his 1,000-yard season last year despite missing four games with a knee injury. A full season from Chubb likely pins him near the top of the race for a league rushing title, while Hunt is still very much considered one of the top running backs in the league. Both Chubb and Hunt are capable of pulling off 1,000-yard rushing seasons — a feat only seven rushing duos have ever accomplished in NFL history — and that'll be even more within reach with the addition of a 17th game to the schedule. If the duo comes anywhere close to reaching that mark, the offense should be in great shape.

The X-Factor: Chubb, and the stats from his four-game absence last season provide all the evidence. When he missed Weeks 5-8 with a knee injury, the Browns' rushing attack sputtered to its lowest four-game output of the entire season. The unit failed to rush for less than 100 yards in three games last year, and two of them were when Chubb wasn't available. That's not to say Hunt isn't capable of doing the job alone — he still averaged just below 4 yards per carry in those four games, and the Browns played the NFL's top rushing defenses twice in that stretch — but when Chubb is on the field, the offense is significantly more explosive.

The biggest number: 23. That's how many combined touchdowns were scored between Chubb and Hunt last year, which accounted for nearly half of the Browns' 50 total touchdowns that helped them finish with the 14th-best offense in the league.

Says it all: "I think we felt very comfortable with how we used them last year – kind of the one-two counter punches and keeping them both fresh as long as we could into each game. However, you want to put your most-talented players on the field, and Kareem is definitely deserving of getting playing time, along with Nick in certain packages. Those are things we have looked at in the offseason and will continue to grow." - offensive coordinator Alex Van Pelt

How many were kept on the initial 53-man roster last year?: 3