Miami’s tightrope walk of a season just lost its safety net.

With an injury to starting quarterback Stephen Morris and an 18-14 home loss to North Carolina, the Hurricanes went from gunning for their first-ever ACC Coastal Division title to hoping this won’t be the worst-ever October.

Florida State is up next, and Virginia Tech after that. If an ankle injury of unknown severity keeps Morris out, or seriously limits his skills, the Hurricanes may soon be looking back on Saturday’s frustratingly-close loss to a batch of Butch Davis’ old recruits as the good old days.

“Stephen will be OK,” Miami running back Mike James said of Morris, who collapsed to the turf just as this game was getting interesting with 8:26 to play. “Stephen’s a tough guy.”

No argument here, but what about the rest of the team? Until now, humiliating losses to Kansas State and Notre Dame didn’t kill the season because they were nonconference opponents. Until now, even a stumble against North Carolina might have been palatable because the Tar Heels are on NCAA probation and can’t prevent Miami or anyone else from winning the Coastal title.

The Morris injury changes everything that was hopeful about the 4-3 Hurricanes and puts even more attention on everything that is putrid.

Foremost on the lousy list is the Hurricanes’ defense, which needed every break it could get to stay in this game. North Carolina rolled up 486 yards of total offense and got stuck on 18 points only because of two missed field goals and a touchdown called back by a holding penalty.

What’s more, Tar Heels running back Giovani Bernard, a Broward County kid, ran for 177 yards and two touchdowns. That’s more ground than any one man has covered against Miami this season, and we’re talking about a Hurricanes defense that ranked 116th out of 120 major-college teams against the run going into the game. Rock bottom, in other words, may not be far away, and FSU will be happy to point the way next Saturday night on national television.

“We’re playing a lot of guys that are learning,” said coach Al Golden, who has played 21 freshmen this season, including two new ones against North Carolina. “They have to continue to grow. … They’re playing a tough schedule, and it’s not getting any easier this week.”

Neither is it getting easier for Golden to find the silver lining. Even fundamental strategy decisions are being taken from him because of mediocrity at key positions like that of placekicker.

Down by four points in the fourth quarter, Golden decided against a couple of long field-goal tries that might have given backup quarterback Ryan Williams all he needed to pull out a miracle win at the end.

As it was, nothing but a touchdown would do for Miami on a last-ditch drive that started with 1:47 to play and made it all the way to the Tar Heels’ 35-yard line before fizzling out with a sack and three incompletions.

But what if Golden could have trusted Jake Wieclaw, 8-for-13 kicking on the year and 0-for-3 outside 40 yards, to make a pressure field goal on a blustery day? Because he couldn’t, Miami punted from North Carolina’s 33 and went for it unsuccessfully on fourth down at the Tar Heels’ 26.

“Al’s got them playing hard,” said North Carolina coach Larry Fedora, once Ron Zook’s playcaller at Florida. “They’re really young, but they’re really athletic and they’re going to be really good in the future, no doubt about it.”

These are nice words, but playing nice is not on the mind of any Miami opponent.

The Tar Heels, for instance, were in a bullying mood from the start, picking up two roughing the quarterback penalties in the first half and one for roughing the punter. On one of them, Morris was grabbed by a blitzing linebacker, which is common enough. The continuation of the play, however, was particularly malevolent, with Morris’ helmet being ripped off and flung several yards in the same angry motion.

There was a time when the Hurricanes reveled in such nastiness. Instead, it is North Carolina on probation, a group of players out to make other teams as miserable as they are. Instead, it is North Carolina racking up 140 yards in penalties and overcoming it all with superior talent.

When run-of-the-mill ACC teams start looking like Miami, and when Miami starts looking like run-of-the-mill ACC teams, the college football world truly is upside down.

Williams, a redshirt sophomore transfer from Memphis, believes he is up to the task of facing FSU if Morris is unable to start. He certainly won’t be surprised by the intensity of the rivalry, having won a state title at Miramar High School.

“This is kind of what I grew up watching,” said Williams, who started 10 games for a 1-11 Memphis team in 2010. “I always wanted to play in a Florida State-Miami matchup. … It’s gonna be fast. It’s gonna be a big show. It’s gonna be a great game. If I play, I’m excited.”

What would excite Golden the most right now is a bye week, but the 6-1 Seminoles are standing between here and there. Morris is a mystery and the Miami defense, unfortunately, is not, and there is little time to do much about any of that.