OXNARD, Calif. -- The Dallas Cowboys open 2021 NFL training camp Wednesday at River Ridge Residence Inn. Here's a closer look at a few storylines:

What bears watching regarding quarterback Dak Prescott's return from a fractured and dislocated right ankle?

Prescott helped erase any questions about the stability of his ankle during the Cowboys' organized team activities and minicamp this offseason. He was kept out of 11-on-11 drills only as a precaution; not because he was not fully ready to go.

Heading into training camp, the plan is for Prescott to practice every day, but coach Mike McCarthy said the club will be smart and give Prescott time off if he needs it. The Cowboys do not plan to practice more than three straight days while in California as they settle in with the Hall of Fame Game on Aug. 5 and a one-day practice against the Los Angeles Rams. Prescott said any residual body soreness subsided as the spring workouts went on, but he will continue to do a more involved pre-practice warm-up to make sure everything is fine.

The next question to answer will be how much work will the Cowboys give Prescott in the preseason games.

How will coordinator Dan Quinn get the defense back to respectability after a disastrous 2020 under Mike Nolan?

There really is no other way to describe last year's defense. The odds that every defender regressed in 2020 seem remote. The match between the skill level and Nolan's scheme was made worse by the lack of an offseason program and preseason games because of the coronavirus pandemic.

The Cowboys won't have that worry this year. Quinn is returning the Cowboys to a familiar scheme with subtle tweaks. The players have raved about his teaching style, willingness to work and ability to adjust. If they weren't saying those sorts of things, then it would be bad. The proof will be when the games start.

The Cowboys don't have to become an impenetrable unit. They just need to be respectable, especially considering the offense's ability to put up points. Quinn is the most important addition the Cowboys have made this offseason.

Can the Cowboys' offensive line return to being one of the best in the NFL again?

For the Cowboys to succeed, it must. Will they ever be as good as they were when Tyron Smith, Travis Frederick and Zack Martin were considered the best at their positions? Probably not, but that speaks to how good that line was.

But, can they be "one of the best," as the question asks? Yes. It will mainly come down to the health of the linemen, and the smile on Smith's face this offseason was telling. He played in two games last season because of a recurring neck issue that has bothered him for a good portion of the past five years. Offensive tackle La'el Collins did not play at all because of hip surgery, but he has dropped weight and impressed McCarthy with his movement. Martin remains either the best or second best guard in the NFL.

Tyler Biadasz will head to camp as the starting center and was looking comfortable in that role last season before a hamstring injury sidelined him for four games. Connor Williams remains the incumbent at left guard but could be pushed by Connor McGovern.

Will running back Ezekiel Elliott rebound from a subpar season?

There is no way to sugarcoat Elliott's 2020 season. It was far from what was expected and made worse by a high-priced contract. He had a career-low 979 yards and lost a career-high five fumbles. He had two 100-yard games and three carries of 20 yards more.

It's too easy to count him out and the five games he played with Prescott last season might be proof, although the fumbles were troubling. He was on pace for a 1,165-yard season with Prescott on the field. While not quite the dynamic statistics of his first four years, it was still good enough when realizing just how bad the defense was at the start of the 2020 season and the deficits the offense faced.

In the spring, Elliott looked to be moving well. Teammates said he is in great shape and eager to show he has a lot of high-level play left in his career.