There are only so many opportunities an NFL player gets to prove he could, or should, become a respected NFL starter.
For some, that window stays open longer than others, especially in the case of an early draft pick. But eventually a player's standing on the hierarchy of the depth chart comes down to whether or not he can get the job done.
The Dolphins have been searching for a pair of respectable offensive guards ever since Justin Smiley and Donald Thomas manned that 2009 offensive line that paved the way for 2,231 rushing yards and 22 rushing touchdowns.
Since then, the Dolphins have put a hodgepodge of 300-plus pounders out there, and they have produced unflattering results. And this year's early guard combo of Dallas Thomas and Billy Turner appears to be no different.
Thomas, a 2013 third-round pick, was a turnstile in 2014, allowing seven sacks in the nine games he started. And Turner, Miami's 2014 third-round pick, played only 17 snaps his rookie season because the coaches felt he wasn't ready.
Yet somehow this duo is first in line to start in 2015.
"We believe these guys have talent," general manager Dennis Hickey said of Thomas and Turner. "They just have to take the next step. Our coaches have to get these guys to take that next step."
Their ability to do so is critical to the Dolphins' success, considering Ryan Tannehill has been the most sacked quarterback in the NFL over his three seasons in the league.
Last year, Tannehill was sacked 46 times, got hit another 50 times, and hurried another 150 times. That means Tannehill had a disturbed pocket on an eye-opening 39 percent of his passing attempts.
Every quarterback faces adversity, and those who handle that adversity best are usually viewed as the league's elite. But it's glaringly obvious that Tannehill's troublesome offensive lines could be holding him back. And what's even more alarming is that the Dolphins' decision-makers haven't done much to address the problem this offseason.
The Dolphins didn't re-sign veteran starters Daryn Colledge and Samson Satele. They also cut Shelley Smith, who was decent as a starter for three games last season.
Veteran linemen J.D. Walton, Jeff Linkenbach and Jacques McClendon were all signed to one-year deals, and the Dolphins selected former Arizona State standout Jamil Douglas in the fourth-round of the 2015 draft.
All of those players will be in the offensive guard mix eventually, but Hickey said Thomas and Turner warrant the biggest investment of playing time this offseason.
"Both are big guys, athletes who are light on their feet and have length. It's just a matter of improving their consistency in their play," Hickey said. "With fairness to Dallas, we have to have him play in one spot, at guard."
All seven of the sacks Thomas allowed last season were given up as a right tackle, where he was filling in as a starter for the second half of the season. He's already moved back to left guard, which is the position he played at the University of Tennessee, and he is settling in.
But are we seriously going to pretend moving Thomas back to a position he's already struggled at will be the answer? After all, Thomas has fought for and lost a starting spot four times in two years.
"There is no substitute for game time. I don't think there's any question," offensive line coach John Benton said of Thomas' 695 snaps last season. "At this point last year to this point this year, his knowledge of the game is so much better. ... I think it's a world of a difference."
The Dolphins need for that to be the case. Because if this franchise is ever going to get to the next level, if Tannehill is ever going to lead Miami to the postseason, they must have solid protection up front.
The average NFL starting quarterback was sacked 35 times per season for the past three years. Tannehill has averaged 46 sacks during that span.
That's 11 more drive-killing sacks per season, 11 more opportunities for the quarterback to get hurt. That should make us all wonder why the Dolphins keep rolling the dice with questionable guards.