In about 36 hours Sunday and Monday, the balance of power shifted dramatically in the American Football Conference, with the needle suddenly pointing directly toward Florida.

It began with New York Jets quarterback Vinny Testaverde rupturing his left Achilles' tendon, continued with the Jacksonville Jaguars crushing the San Francisco 49ers and ended late Monday night with the Miami Dolphins' 38-21 victory over the two-time defending Super Bowl champion Denver Broncos at Mile High Stadium.

Testaverde is gone for the season, as is Jets third-down running back Leon Johnson, who suffered a knee injury in Sunday's loss to New England. Wide receiver Wayne Chrebet will be out for another five weeks with a broken foot, and without those three, the Jets go from Super Bowl hopeful to just another team scrambling to get a wild-card berth.

The Broncos look as if they will be hard-pressed to accomplish an unprecedented Super Bowl three-peat, though new starting quarterback Brian Griese showed plenty of promise in his three-touchdown, no-interception performance. Still, people who have been around the Broncos all summer say there is not the same sense of urgency among the players, a common occurrence with defending champions, though Coach Mike Shanahan is as intense as ever.

The same can be said of Jacksonville's Tom Coughlin and Miami's Jimmy Johnson, only their teams are responding. The Jaguars, in their fourth NFL season, were built to last, and as long as they can keep quarterback Mark Brunell and running back Fred Taylor healthy, they have to be considered Super Bowl material.

The Dolphins may be approaching elite status. Quarterback Dan Marino, at 37 the NFL's oldest starter, and a rookie-charged running game sliced through the Broncos.

During the offseason, the Dolphins added deep-threat wide receiver Tony Martin and enlivened their previously anemic running game by drafting fullback Rob Konrad and tailbacks J.J. Johnson and Cecil Collins.

"Tony Martin is better than even I thought," Jimmy Johnson said. "Our guys were very confident. We told them before the game, `Just show people how good you are.' I think we did that. We're going to have a good football team, if we can keep it going."

Jets Mirer-ed in Doubt

Rick Mirer, the Jets' starting quarterback for the moment, is not Testaverde, who led the team to last season's AFC championship game. Mirer, like Testaverde a highly touted first-round draft pick, hasn't won a game in three years, and coaches and personnel men around the league say they believe he may be so beaten down by past failures that he may not last the season as the starter.

Testaverde hardly was a one-year wonder last year. He made the Pro Bowl with the downtrodden Baltimore Ravens when he had far less talented teammates, and over the past five years, he has become a vastly improved player who fit perfectly into Jets Coach Bill Parcells's offense.

Sources said today that Parcells has spent the past day pursuing possible trades for veteran quarterbacks now in backup roles, including Minnesota's Jeff George and Kansas City's Warren Moon. But he may wait a week or two to see how Mirer handles the team and the pressure. He also has serious salary-cap problems that would force him to cut several players to get a proven quarterback.

Jeff Hostetler is an unrestricted free agent after the Washington Redskins waived him during the offseason. He came off the bench in 1991 to help the Parcells-coached Giants win the Super Bowl when Phil Simms was hurt. Hostetler did not go to a training camp this summer. He helped his 8-year-old son Tyler rehabilitate from serious injuries suffered in an all-terrain vehicle accident June 14.

As of today, Hostetler had not yet been contacted by the Jets. A source close to Hostetler -- who was pursued before the accident by San Francisco, Seattle, Tennessee and St. Louis -- said today that if Parcells wants him, Hostetler would consider playing in New York.

The Rams also are desperate for quarterback help since Trent Green suffered a season-ending knee injury during the preseason, and Hostetler talked to them. But he probably won't be prepared to play for another two or three weeks.

Dolphins Weather Storm

The Dolphins' ability to concentrate at typically roaring Mile High Stadium on Monday night was even more impressive considering the situation back home, where Hurricane Floyd had been forecast to hit South Florida until it veered north today.

Still, many Dolphins players, coaches and officials had scrambled to move their families awy from potential harm. The team's chartered plane, originally scheduled to land in Fort Lauderdale, instead landed in Fort Myers, about two hours west, and the team rode buses back to the Miami area when it became apparent the hurricane would not make a direct hit there.

With a short week, hurricane or not, Johnson and his staff went straight from the bus to the practice facility and began preparing for their home opener Sunday against the Arizona Cardinals. They landed at 6 a.m., and were at their desks and tape machines by 9. The players had the day off.

Cavalier to the Rescue

When former University of Virginia wide receiver Herman Moore suffered a knee injury eight minutes into Detroit's 28-20 upset of Seattle, he was replaced by another former Cavalier, second-year man Germaine Crowell.

"When Herman went down, I think I realized that someone was going to have to step up and make some plays," said Crowell, who caught touchdown passes of 16 and 41 yards. "But everyone got more focused and made plays."

Crowell will have to keep succeeding as the Lions' deep threat. Moore is expected to be out between three and five weeks. . . .

The Patriots' leading rusher against the Jets was former Redskin Terry Allen. He had 54 yards on 15 carries, including a 22-yard scoring run that gave New England a 24-16 lead. . . . Cardinals wide receiver Rob Moore, after ending his holdout late in the week, had three catches for 77 yards and one touchdown in Sunday's comeback over Philadelphia. "I'm sure glad he was here because I don't think if Rob wasn't here we would have won the football game," Coach Vince Tobin said. By the way, third-year quarterback Jake Plummer has led the Cardinals to 26 wins, 10 of them on comebacks. . . . Buccaneers quarterback Trent Dilfer has thrown seven interceptions and two touchdown passes in three games against the Giants.