There are many ways in which pressure can be applied on regular people. And believe it or not, NFL quarterbacks are regular people too.
But then there's intangible pressure, which, again according to Merriam-Webster, is "the burden of physical or mental distress," as well as "the constraint of circumstance" and "the stress or urgency of matters demanding attention."
Let's talk about that second type of pressure—the one you can't measure or necessarily see. Here are the 10 NFL pivots who will face the most of it in 2013.
Is it even legal to make a list like this and not include Dallas Cowboys quarterback Tony Romo? When you run the offense on America's most popular football franchise, you're inevitably going to face a lot of pressure.
Throw in that the 33-year-old Romo hasn't been able to lead "America's Team" to the playoffs since 2009 and that he's now one of the highest-paid players in NFL history, and it's easy to understand why he'll likely be under a lot of pressure to deliver in 2013.
At Cowboys minicamp, Romo addressed the topic head-on by denying that he felt any increased pressure.
"Pressure and fear are all just in your own brain," he said, according to ESPNDallas.com's Calvin Watkins. "To me, it's nothing more than you going out and you're competing your butt off every day and trying to win every day. So I don't allow what outside influences affect my psyche or what my mental makeup is."
Nevertheless, Romo hasn't always risen to the occasion in acute situations that involved perceived pressure. Regardless of whether he feels it or not, it'll exist throughout the 2013 campaign in Dallas.
For two years running, something just hasn't been right with San Diego Chargers quarterback Philip Rivers. The former top-five draft pick has thrown 35 interceptions since the start of 2011. His passer rating was above 101 in 2008, 2009 and 2010, but it has plummeted below 89 in each of the last two seasons.
A.J. Smith, who acquired Rivers in a draft-day trade in 2004, is now gone, as is Norv Turner. A new regime has moved into town—one with no connection to Rivers and the days when he was one of the most productive and consistent quarterbacks in the game.
Back in April, Kevin Acee of U-T San Diego said on NFL Network (per Sports Illustrated) that "2013 is the final audition of Philip Rivers," and that's not far-fetched at all.
With rookie quarterbacks coming cheaper than ever and becoming reliable options faster than ever, the Chargers could be prepared to give up on the 31-year-old Rivers if he doesn't lead them back to the playoffs in 2013.
This is also probably Jay Cutler's final chance to prove that he can be a franchise quarterback in this league, because the 30-year-old is entering the final year of his contract with the Chicago Bears.
According to ESPNChicago.com, Cutler stated in March that he and the team hadn't discussed an extension and suggested he'd play out the final year of his deal in 2013. That alone creates enough pressure to get the former No. 11 overall pick onto this list.
Throw in that he's won only a single playoff game in six years as a starting quarterback and that his passer rating has dropped in back-to-back seasons (in 2012, he was rated below Ryan Fitzpatrick, Sam Bradford and Josh Freeman) and you begin to realize that it's going to be a do-or-die campaign for Cutler.
While Atlanta Falcons quarterback Matt Ryan and Baltimore Ravens quarterback Joe Flacco came into the league together in 2008, Ryan's rookie deal was one year longer. As a result, Flacco is swimming in cash right now while Ryan and the Falcons continue to work to see if they can avoid a contract year in 2013 and a potential franchise tag situation in the spring of 2014.
Pro Football Talk's Mike Florio reported this week that "casual talks currently are occurring, with an expectation that things will heat up after the July 4 holiday."
If Ryan doesn't come to terms with the Falcons this summer, he'll enter 2013 knowing that every throw he makes could make or cost him big bucks. That worked out well for Flacco, who became a Super Bowl MVP in his contract year, but Ryan might not react to that pressure in the same way.
And if Ryan does come to terms with the team before the start of 2013, he'll be faced with having to live up to a contract that will surely make him one of the richest players in the league. That's pressure too, especially when you have just a single playoff victory in five tries.
Forget the money; he'll have a ton of pressure on him regardless next season. The franchise is starving for a Lombardi Trophy, and the 28-year-old Ryan is smack dab in the middle of his prime.
For Philadelphia Eagles quarterback Michael Vick, the pressure is already on. That's because he's yet to earn the starting job for the 2013 season.
Even if the soon-to-be-33-year-old wins a training camp battle with Nick Foles, Matt Barkley and Dennis Dixon, don't expect the pressure to disappear. He'll be forced to adapt to Chip Kelly's brand-new offense while some or all of those younger quarterbacks continue to breathe down his neck.
Vick has missed 13 games due to injury since he became the team's starter in 2010, and he has turned the ball over 33 times in 23 games since the start of the 2011 campaign. He's also slated to hit free agency next offseason, so he'll also be forced to prove that he can stay healthy and can avoid costly mistakes while playing for one final big contract.
On the bright side, Snoop Lion is firmly in his corner.
Tampa Bay Buccaneers quarterback Josh Freeman is entering the final year of his rookie contract, but he has stated that there's no extra pressure resulting from that scenario.
"It doesn't change anything for me,'' Freeman said in April, according to Ira Kaufman of the Tampa Tribune. "Worrying about external forces won't help you play better. Talking to different guys, it's all set up to be a high-stress situation. But, honestly, I know that's stuff I can't control right now."
What Freeman can control—to an extent, anyway—is whether he finally becomes a franchise quarterback or just another borderline starter and journeyman. This will likely be the year in which the 25-year-old establishes himself as one or the other.
Freeman was excellent in 2010, but he's thrown a league-high 39 interceptions since then, and the Bucs used their second pick in the 2013 draft on a new quarterback, Mike Glennon out of North Carolina State.
If Freeman doesn't deliver this year, look for the team to go in a new direction next offseason.
Detroit Lions quarterback Matthew Stafford might not be fighting to keep his job, and he might not be a free agent until 2016, but that doesn't change the fact that Stafford faces a lot of pressure to step his game up in his fifth NFL season.
When you're a 25-year-old former No. 1 overall draft pick and you have the best receiver in the game to throw to, there's no excuse for a 79.8 passer rating and a sub-60 completion percentage. In order to become elite, Stafford has to become more consistent, increasing his accuracy and decreasing his interception totals (he's thrown 33 picks since the start of 2011).
Both Stafford and the Lions took a step backward in 2012, one year after breaking a decade-long playoff drought. But the team is still 22-42 since drafting Stafford, and the Lions are an abysmal 1-23 against winning teams (including a playoff loss) with him under center.
If things don't change this year and Stafford and the offense don't take better advantage of a player like Calvin Johnson, the heat will be turned up.
With a bad offensive line and limited support, Indianapolis Colts quarterback Andrew Luck fared quite well in his rookie season. But with the line receiving some upgrades in free agency and the team looking stronger and deeper now, everyone will expect the 2012 No. 1 overall pick to take a major step forward in 2013.
That means that if Luck were to experience even a mild sophomore slump, he'd likely already begin to face questions regarding his ability to live up to the tremendous amount of hype that surrounded him coming out of Stanford.
Last year, the Colts rode a last-place schedule and a lot of momentum into the playoffs despite the fact they allowed 30 more points than they scored. That's great, but it also adds to the pressure Luck will face as fans expect another double-digit win total and another playoff appearance in 2013.
Such results won't be easy to come by.
The Baltimore Ravens rolled the dice on Joe Flacco in 2012, allowing him to play out his rookie contract under center. That paid off on the field, with the Ravens capturing the Lombardi Trophy, but it cost the team big bucks on paper.
For a brief time after signing a lucrative new deal earlier this offseason, Flacco was the highest-paid player in NFL history. That title belongs to Aaron Rodgers now, but regardless, Flacco's making $20 million a year...and he's now faced with having to live up to that contract.
Not only does he somehow have to prove he's worth that kind of money, but Flacco also has to show the world that his uncharacteristically fantastic performance in the 2012 playoffs wasn't a fluke. Yes, he had a ridiculous 11-0 touchdown-to-interception ratio while leading the Ravens to the Super Bowl, but let's not forget that the 28-year-old has never been an All-Pro or a Pro Bowler and has a career passer rating of just 86.3.
The pressure's on Flacco now to become an elite quarterback on a consistent basis.
Erik James Manuel was the only quarterback selected in the first round of this year's NFL draft. That alone creates pressure.
Nowadays, though, there's more pressure than ever on rookie quarterbacks to win starting jobs and perform like veterans immediately, and Manuel will be faced with that onus in Buffalo, where the Bills crave a franchise quarterback after missing the playoffs for the 13th consecutive season.
The bar has been raised by recent rookie signal-caller success stories such as Andrew Luck, Robert Griffin III, Russell Wilson, Cam Newton and Andy Dalton, but Manuel still has to beat out veteran offseason acquisition Kevin Kolb in order to earn the starting job with the Bills.
Those two basically split reps during organized team activities, but Manuel probably still has some ground to make up in training camp. If that doesn't happen and he can't supplant Kolb early, the No. 16 overall pick out of Florida State will already begin to face criticism.