“Take advantage,” he told his players. “This is your chance to show us what you can do.”

In a normal year, teams must finalize their 53-man rosters shortly after the fourth preseason game. This season, without any preseason games, they have until Saturday at 4 p.m. Despite the time left, Washington held its most important practice of the year almost a week in advance because of what comes next. Rivera wants Monday’s walk-through at FedEx Field to be a logistics dry run, and he hopes the practices Wednesday through Friday will help the team settle into a game-week routine. This meant competition Sunday — and difficult choices ahead.

By now, Washington knows who its top players are at each position. But the trouble in evaluating special teams without preseason games leaves Washington, like other teams, in a difficult spot. For example, if a player is fourth- or fifth-best at his position, but special teams coach Nate Kaczor does not rank the player highly — and Rivera has Kaczor rank every player’s special teams abilities — the personnel staff must choose between depth and versatility.

“I can’t hold Nate hostage and not give him guys that will help us [on special teams],” Rivera said. “So, we’ve got some tough decisions.”

In its best attempt to understand what it has, Washington emphasized special teams Sunday. The team drilled kickoff, kickoff return, punt, punt return, field goal, field goal block, onside kick and safety coverage. Rivera might examine wide receiver Cam Sims and defensive end Jordan Brailford, two fringe players Kaczor focused on. Their previous experience — Sims is in his third season, Brailford his second — is attractive because, especially this offseason, coaches want players who have proved they can perform under the bright lights.

Yet without games, Rivera acknowledged evaluating special teams is an inexact science.

“You won’t really know until the young man you decide to keep . . . is out there,” the coach said. “On the first Sunday, you’re going to find out exactly whether or not he has what it takes. Right now, you’ve kind of got an incomplete picture.”

On offense and defense, Sunday cemented what seemed likely throughout camp. There was noteworthy contact, like when defensive end Chase Young pile-drove running back Adrian Peterson into the dirt, or when defensive tackle Jonathan Allen limped off with a hurt left leg (he’s OK), though most of the position battles seem all but over. Geron Christian at left tackle, Wes Martin at left guard, Troy Apke at free safety, etc. The remaining questions are down the roster at wide receiver, linebacker, cornerback and tight end, and it could include a player such as wideout Isaiah Wright.

In conversations with Kyle Smith, vice president of player personnel, Rivera said they have mapped out different versions of the roster. This season, Rivera has emphasized that it will be crucial to stay deep at certain positions, though it seems as if Rivera has not decided which positions yet.

“We’ve got a way to go still,” Rivera said. “We’re in the process of developing this football team. But the process is we have to take a step forward every day. We can’t go backwards.”

After practice, Rivera seemed excited to review the tape. There were “some things we need to get corrected,” he said, but he praised his players’ effort. The only exception was three series after the “halftime” they simulated in the middle of their practice situations. Rivera thought “there was a little bit of a lull,” which he’d seen before and did not like. He scolded his team for the lack of focus.

“I just wanted to make a point in those things,” Rivera said.