The NFL made it to the playoffs despite the coronavirus. But plenty of obstacles remain.

But no one within the sport is ready to take a victory lap just yet.

“We have even a greater challenge, I think, ahead,” said DeMaurice Smith, the executive director of the NFL Players Association.

The NFL will continue to trust in a strict and ever-tightening set of protocols that has included daily coronavirus testing, rigid mask-wearing and distancing measures, sophisticated contact tracing using electronic tracking devices and genomic-sequencing tests to identify different strains of the virus — and, for the most part, a high degree of buy-in from participants.

“We’ve done really well to get here to this point,” Cleveland Browns center JC Tretter said. “We’ll need continued vigilance, continually following the protocols, making the right decisions.”

Tretter is the NFLPA’s president. Yet his team is far from immune from coronavirus issues. Coach Kevin Stefanski will miss Sunday night’s opening-round playoff game at the Pittsburgh Steelers after testing positive. The positive test results continued to come for the Browns, who played their second-to-last game of the regular season soon after placing six players on the covid-19 reserve list.

“I think what this proves is … even when doing all the right things, this virus is so contagious that it doesn’t guarantee you full protection,” Tretter said.

Stefanski called it “just the nature of the beast this season.” He added that the Browns have done their best — they “haven’t had an in-person meeting with players in months,” he said — and that “it is frustrating” to have issues arise nonetheless.

“We’ve tried to go above and beyond, tried to do the right things,” Stefanski said. “And we’re going to continue to do that. You really have to double down on the protocols and trust the protocols and make sure that everybody’s safety is priority number one.”

No refresher course was required on just how quickly things can turn dire, Steelers Coach Mike Tomlin said.

“We have daily, continual reminders of how fragile these circumstances are,” Tomlin said. “Every morning at 6 a.m., I am looking at my phone, waiting for verification of the previous day’s test results. You know, are we in the clear or are we not? And what necessary adjustments need to be made? What investigations, if any, need to be made? That has been our life … since July.”

The NFL says it will continue to employ the scheduling approach it used during the regular season: Any game postponements would result only from medical considerations, based on ongoing concerns about an outbreak with unchecked transmission of the virus. No game will be postponed over a competitive issue related to contact tracing — as when the Denver Broncos played a game in November without all four of their quarterbacks or the New Orleans Saints played Sunday without four running backs.

“Competitive concerns haven’t weighed into it,” said Jeff Miller, the NFL’s executive vice president of communications, public affairs and policy.

What if a megastar quarterback such as the Kansas City Chiefs’ Patrick Mahomes or the Green Bay Packers’ Aaron Rodgers were to be contact-traced out of a postseason game? It could happen. Smith said he’s aware of the increased potential “angst” among fans if that were to happen in the playoffs, but the NFLPA endorses the league continuing its regular season approach.

“I think it stays with how we’ve handled it all year. … When it comes to competitive advantage, that’s not how we’re going to make decisions,” Tretter said. “We have to continue to make decisions through a health and safety lens.”

The NFL dealt with two major coronavirus outbreaks during the season, one on the Tennessee Titans in late September and early October and one on the Baltimore Ravens in late November and early December. The Titans ended up playing a rescheduled game on a Tuesday. The Ravens played on a Wednesday and then on a Tuesday. That type of creative date-juggling becomes much tougher now.

“The reality of where we are now in the playoffs and given the tighter window, a lot of those contingencies that we would have had in the regular season are things we probably don’t have [to] the same level … during the playoffs leading up to the Super Bowl,” Smith said.

Smith said he hasn’t had any conversations with the league about contingency plans involving the playoffs or Super Bowl being pushed back. But during this unusual season, you never say never.

“We’ve gotten to where we are,” Smith said, “because we’ve kept a lot of options on the table. … When we say it’s day-to-day, week-to-week, we actually mean it’s day-to-day and week-to-week.”

The NFL, as the nation’s most popular and prosperous sports league, has been able to devote abundant resources to operating during the pandemic. It administered 922,220 coronavirus tests to players, coaches and team staffers between Aug. 1 and Jan. 2, according to testing results announced by the league and union.

But resources alone weren’t enough. The NFL and NFLPA also had to tweak as they went.

“I think we’ve tried at all points to be flexible and adaptable, to learn from the cases where we have seen transmission,” said Allen Sills, the NFL’s chief medical officer. “And, really, the early outbreaks that we had … were very instructive in that way.”

The key modification came in October, when the league began mandating five-day quarantines for individuals classified as high-risk close contacts. It amounted to a trade-off: There would be more competitive problems and, undoubtedly, more grumbling about perceived injustices. But in return the NFL reduced the chances of teams regularly suffering significant outbreaks.

“That’s probably the single greatest evolution we’ve seen,” Miller said of the league’s contact-tracing efforts.

Sills called that endeavor “a 24-hour-a-day, seven-day-a-week operation.” The league’s contact-tracing team was at work even on Christmas Day. “They’ve been absolute warriors in helping us to get to this point,” Sills said, adding that the proof of the effectiveness of the effort is that more than 30 of those individuals classified as high-risk close contacts subsequently tested positive.

“That means there are 30 different cases that would have been inside our facility had they not been identified and isolated,” Sills said recently.

In the most recent results announced by the NFL and NFLPA, there were 34 new confirmed positive test results among players and 36 new confirmed positives among other personnel in testing between Dec. 27 and Jan. 2. That was up from 58 total positives (for 21 players and 37 non-players) in testing between Dec. 20 and Dec. 26.

But the NFL and NFLPA have not reversed their decision to eschew a postseason bubble. Neutral-site bubbles would have been logistically difficult for the NFL, given the size of a team’s operation. The league, while barring mandatory home-market bubbles, left open the possibility of teams using local bubbles on a voluntary basis. But the playoff teams have not gone that way. League and union leaders questioned whether bubbles would be more effective and expressed wariness about putting players and team staffers into such social isolation.

“The voluntary bubble still has the same dependency on personal accountability,” Tretter said.

Planning is proceeding for a Super Bowl that will be conducted in far less grandiose fashion than those in previous years. Seating capacity at Raymond James Stadium will be limited, although the NFL has not specified yet how many fans will attend. The teams are expected to arrive in Tampa late in the week. Reporters’ access to players and coaches will be remote.

For 18 of the 32 NFL teams, the season already is done. By the end of this weekend, the playoff field will be pared to eight teams. The end is so close.

“I think it’s been a herculean effort by all involved in every aspect,” said Dawn Aponte, the NFL’s chief football administrative officer.

Yet that end is — even now — so far away, with many remaining chances for coronavirus calamities. Those in the NFL at least can draw on what has been accomplished since teams began gathering for training camps in late July.

“The only way to even have a chance to play this game week-to-week was just to accept the fact that we were not going to question our scientists,” Smith said. “We weren’t going to question the data. We were going to put all the political stuff that you’ve seen play out in the rest of the country to the side. And we were going to do everything within our power to keep our players safe and to try to engage in this business.”