The offense will make or break the St. Louis Rams' 2015 season. Since quarterback is the most important position on offense, we can assume all eyes will be focused on the red shirts at training camp.
It's an exciting year for the position. The Rams have two new faces under center in Nick Foles and Sean Mannion—three if you count Case Keenum, who made a brief appearance on St. Louis' roster at the beginning of the 2014 season.
Sam Bradford has been the team's No. 1 quarterback for five years, so it truly is the end of an era. A fresh start at quarterback always fills a fanbase with hope and optimism.
The Rams have extraordinary talent on defense and a revitalized run game. With those two components already in place, a competent quarterback may truly be the ultimate difference-maker. It could be the factor that determines if the Rams are in for a playoff year or just another disappointing season.
With that in mind, here's a look at St. Louis' quarterback depth chart:
Starter: Nick Foles
Trading for Foles was a brilliant move for multiple reasons.
For starters, it was just a great deal overall. According to ESPN.com, the Rams get the Philadelphia Eagles' second-round pick in 2016 no matter what. In a worst-case scenario (if Bradford does not play at all next season), the Rams surrender their third-round pick in 2016. It becomes a fourth-rounder if he plays less than 50 percent of the snaps, and the Rams give up nothing if he goes over 50 percent.
The Rams also received Philadelphia's fourth-round pick in 2015, which was used to draft Iowa offensive lineman Andrew Donnal.
Even the Madden video game would probably balk at such a one-sided trade. Les Snead continues to be a smooth negotiator. He took Washington to the bank in 2012 with the Robert Griffin III trade, and he has apparently worked his magic yet again.
It's also a great trade simply due to the overall loss of anxiety. Rams Nation is tired of holding its breath every time Bradford takes the slightest hit. Swapping Bradford for the less injury-prone Foles will do wonders for St. Louis' collective cardiac health.
With Foles, there's some risk involved.
According to NFL.com, he suffered a hand injury as a rookie in 2012. In 2013, during his breakout season, he experienced some concussion symptoms. This past season, Foles only started eight games after going down with a broken collarbone.
Overall, Foles has missed nine starts in his 27 games since taking over as the Eagles' starter in Week 6 of 2013.
That's a far cry from Bradford's three season-ending injuries in the last six seasons, dating back to college. But Foles' three injuries in three seasons is still a concern.
Also, it's fair to say that Foles isn't a guy who can elevate the offense on his own. He will need an excellent supporting cast in order to return to his 2013 form.
Foles was impressive during his 2013 Pro-Bowl campaign, but many forget that Philadelphia also featured the No. 1 rushing attack in the NFL that year. If the Rams want Foles to return to that level, they'll need to ignite the run game.
If the run game is healthy and productive, and the young offensive line isn't a total liability, there's no reason why Foles shouldn't perform at an excellent level in 2015.
Backup: Case Keenum
Bringing in Case Keenum was an extremely intelligent move. Not only is he an experienced and capable backup, but he also has the talent to potentially be a long-term starter someday.
The Rams entered the offseason well aware that they needed multiple answers at quarterback. There were no prized franchise passers on the free-agent market, and the Rams weren't in a position to draft one of the top rookies.
Instead, the Rams made do and traded for Foles. That was a great start, but not nearly enough. That's why they also acquired Keenum for a 2016 seventh-round pick, per the team website.
Keenum took over the as the Houston Texans' starter in 2013 for eight games. The Texans were the worst team in the NFL that year with a 2-14 record. He had a poor supporting cast but still made the best of it.
Keenum turned in two three-touchdown games and exceeded 200 yards passing four times. He had Andre Johnson and a rookie DeAndre Hopkins at his disposal, but he had little help from the run game. Arian Foster missed seven of those eight games and had just four carries during that stretch.
We have yet to see what Keenum can do with a competent run game backing him up. If Jeff Fisher's vision of an elite rushing attack centered around Todd Gurley comes to fruition, that could be the career boost Keenum needs.
Given Foles' injury history, it's highly likely that the backup will start a handful of games for St. Louis. That's why the addition of a competent No. 2 was so vital for 2015.
Hopefully, Keenum is that guy.
Third String: Sean Mannion
Foles and Keenum are young veterans with great potential and have game-day experience. That's exactly what the Rams needed, but the addition of a rookie developmental project was also important.
To answer that need, the Rams used a third-round selection on Oregon State's Sean Mannion.
Mannion was not the most electric or talented passer from the latest draft class. He was held under 20 passing touchdowns in three of his four seasons as a starter. He also coughed up 54 picks and 27 fumbles—only nine were lost—in 47 games.
However, it's important to consider the context.
His top receiver in 2014 was Victor Bolden, who stands in at only 5'9" and under 180 pounds. Meanwhile, his top running back—senior Storm Woods—contributed just 766 yards on the ground. He also played behind a line that allowed him to be sacked 36 times in 12 games.
The lack of a supporting cast encouraged the Rams to look past the numbers and focus on Mannion purely as a physical prospect. That was probably wise, as his measurables are fantastic.
Mannion measured in at 6'6" and 229 pounds at the NFL Scouting Combine. He has the prototypical size, solid mechanics, sharp accuracy and is experienced in a pro-style system.
The lack of top-notch college production raises questions, but few would argue that he's physically built as a true NFL passer. With proper development, he has a lot to offer.
Mannion will serve as the No. 3 for the time being. But the Rams used a lofty third-round selection to acquire him, so he's obviously part of the long-term plan. He'll eventually become the team's permanent backup with the potential to start someday.
Fourth String: Austin Davis
Austin Davis was thrown to the wolves in 2014. The third-string passer was forced to start after the Rams lost both Bradford and Shaun Hill prior to Week 2.
Regardless, Davis had some admirable moments and was fun to watch.
In a nail-biter against the Tampa Bay Buccaneers in Week 2, Davis led the Rams on a field-goal drive to retake the lead in the fourth quarter with less than a minute on the clock. He also led St. Louis to victory in games against the Seattle Seahawks and San Francisco 49ers.
Davis had several late-game rallies, including nearly wiping out a 34-7 deficit against the Philadelphia Eagles with three unanswered touchdown drives. The Rams got the ball back down by six with just under two minutes left in the game, but Davis and the offense failed to get it done.
Davis is fun to watch. It's just spoiled by that nasty habit of imploding with the game on the line.
The game against the Arizona Cardinals in Week 10 is another example. The Rams entered the final quarter leading 14-10. Davis turned the ball over three times in just over three minutes of play, including a pick-six and a fumble recovery for a touchdown.
The Rams entered the fourth quarter with a lead and a victory in sight. Instead, it was a blowout. St. Louis lost the game 31-14.
Davis flashes Pro Bowl potential when he's on, but he reverts to an erratic mess in crunch time. That's not something this team can tolerate. The Rams are a defensive team that faces low-scoring affairs. St. Louis cannot overcome its offense giving away free touchdowns on a regular basis.
Even so, Davis has talent and will compete in camp as the No. 4 quarterback.
It's possible he still has a shot at the third-string job, but it's not likely. The Rams used a relatively high pick on Mannion, so his draft status will automatically give him an edge over Davis.
Steven Gerwel is the longest-tenured Rams featured columnist at Bleacher Report and served as the Rams' game-day correspondent in 2014. You can find more of Gerwel's work by visiting his writer profile or following him on Twitter.