So much of an NFL coach's longevity hinges on the play of his quarterback. You get good quarterback play and the coach -- or offensive coordinator -- tends to look really good. If you look good, you stay employed or get poached by another team. If your quarterback is shaky or doesn't develop, then the coach won't last.
Typically, when a coach enters the season on the proverbial "hot seat," look at his quarterback. That could dictate whether his seat gets hotter, cooler, or removed all together via pink slip. There are often other reasons -- namely wins and losses -- why coaches are found in dicey positions, but the quarterback could be his life preserver, or his albatross.
Let's take a look at some potentially uneasy coach-quarterback combinations entering the 2011 season and see if we can gauge the safety or potential problems:
Jaguars: Coach Jack Del Rio, QB David Garrard
This situation might be the slickest slope of any in the NFL. Del Rio has been on somewhat unsafe footing for the past two years and this could be a make-or-break campaign. David Garrard, who has been OK but hardly spectacular -- especially the past two seasons (38 touchdowns, 25 picks) -- is also on notice.
The Jaguars picked up former Bills starter Trent Edwards last season and gave him a chance to assume the starting position from Garrard, which he didn't. So Jacksonville drafted quarterback Blaine Gabbert 10th overall in 2011, trading up to get him.
At some point, maybe not this season, Gabbert will be the starter. If things start to unravel this fall, Del Rio might accelerate Gabbert's arrival in an attempt to save his job. Having a rookie with no offseason to learn and grow being the best option for survival is hardly ideal.
Cowboys: Coach Jason Garrett, QB Tony Romo
Tony Romo is back from a broken collarbone that ended his 2010 season, one in which Dallas failed to make the playoffs. The team's failures are only going to add to the pressure for Romo to succeed. Romo is talented but isn't on firm footing. If he fails, there will be pressure for Dallas to cut bait and look to Plan B in the offseason.
Romo will have had his chances. And even though he's a good player, good isn't good enough sometimes in Dallas.
Garrett being an offensive guy compounds the pressure for the unit to succeed. There is really no reason for the Cowboys not to be one of the league's better offensive teams. There is talent nearly everywhere, including quarterback. The defense needs to get up to speed but so does Romo.
Don't think owner Jerry Jones will take missing the playoffs again lightly, especially when potential head coaches Jeff Fisher, Jon Gruden and Bill Cowher will be available.
Dolphins: Coach Tony Sparano, QB Chad Henne
Sparano might have gained financial security with the two-year extension he got this offseason after a clumsy attempt by Dolphins ownership to find his replacement. As we know, though, contract extensions don't insure long-term employment.
Sparano and the Dolphins have aligned themselves fully with Chad Henne, who didn't step up to the task last season when the team threw its support behind him as the starter (14 starts, 15 TDs, 19 INTs, five fumbles, two of them lost) and got him wide receiver Brandon Marshall in a pricey trade. While the Dolphins didn't draft a quarterback, they are expected to explore that option in free agency.
Henne has the potential for sure. He's also stepped up in the offseason to arrange team workouts that have been well-attended. Henne has a new offensive coordinator in Brian Daboll but he hasn't been able to work with him because of the lockout. The Dolphins have solid talent on both sides of the ball and could very well compete for the playoffs in the tough AFC East.
If they really flop, though, and Henne doesn't show much more than he already has, there could be turnover at the top -- and at QB.
Texans: Coach Gary Kubiak, QB Matt Schaub
Kubiak is viewed as a dynamic offensive coach and the numbers prove it. Matt Schaub has helped, emerging as one of the league's most prolific passers the past few seasons. Even so, the Texans have yet to make the playoffs. That inability to get to the postseason could cost Kubiak his job.
Rightfully so, the blame for the Texans' failure to reach the playoffs last season rested on the defense. Houston brought in former Cowboys coach Wade Phillips to run the defense and used its first five draft picks on defensive players, including end J.J. Watt with the 11th overall choice.
Kubiak is secure in knowing that Schaub won't be the reason for his possible shortcomings. He should also be secure in knowing that Schaub should play a sizeable role in helping the Texans finally get to the postseason.
Giants: Coach Tom Coughlin, QB Eli Manning
Coughlin always seems to be in the warm seat in New York, even after the Giants finished 10-6 and second in the NFC East last year. This, despite Eli Manning throwing a career-high 25 interceptions. New York was in the hunt until the end, but that doesn't matter, though. Fans want a return to the Super Bowl and memories are short -- even for a coach like Coughlin who's had just one losing season since taking over in 2004.
Manning's 25 interceptions were uncharacteristic, and the odds of him venturing back into that territory a second straight season are unlikely. Even with his high number of turnovers, Manning threw for more than 4,000 yards and 31 touchdowns. If he's even marginally improved, that could be enough for New York to get back to the playoffs.
If he falters, though, overall or at the most crucial of times, and the Giants don't make it to postseason play, there will be calls for Coughlin to be replaced -- again. It would be the third straight year of not making the playoffs after four consecutive appearances and a Super Bowl championship.
Follow Steve Wyche on Twitter @wyche89.