The San Francisco 49ers have built one of the NFL's best teams, relying on a strong defense and an offense that doesn't make mistakes to carry them deep into the playoffs year-in and year-out. Defensively, it's easy to see where the power comes from: the best group of linebackers in the NFL. On the offensive side of the ball, the team has preached field position, clock management and ball control, and the 49ers have excelled in each of those areas.

They're able to excel in those areas because they've built what is one of the best offensive lines in football today. San Francisco arguably has top five players at all of the left tackle, left guard, right guard and right tackle positions. The right side is manned by Anthony Davis at right tackle and Alex Boone at right guard. At one time, the two might have competed, but the 49ers elected to play Boone, who does not fit the build of a prototypical guard, on the interior.

Deciding to play Boone there ended up being a smart decision, as he has arguably outplayed every other guard on that side in the league. Joe Staley, despite injury concerns here and there, has been a consistent left tackle and one of the best in the league. Mike Iupati, the left guard, is a mauling run blocker and Jonathan Goodwin has been a solid contributor at center.

But the line is expected to undergo some significant changes in the near future. Staley and Davis are both signed for the foreseeable future, but there could soon be discontent with one of those players: Staley. He signed a huge contract that would keep him in town through the 2017 season back in 2009, but he has since outperformed that contract.

Rand Getlin of Yahoo! Sports suggests that the 49ers are considering re-doing Staley's contract "soon." He suggests that the team "recognizes they'd be wise to guard against him becoming disenchanted." The 49ers have often been able to retain top talent with team-friendly deals, but Staley's deal is definitely far south of the league norm at this point.

Staley's base salary does not exceed $6.25 million in any of his remaining four seasons, and his cap hit does not even break $7 million in any of his seasons. In 2014, he's going to earn a base salary of $2.7 million with a cap figure of $3.4 million. Staley ranks 13th in the NFL among left tackles when it comes to average earned per year, and is nowhere near the top when it comes to guaranteed money, either.

It's worth noting that these numbers his are being compared to are from contracts that were signed after 2009. The market has changed dramatically, left tackles are one of the most valued positions in football, and Staley has been consistently ranked among the top tackles in the league in pass protection. He routinely goes against some of the best pass rushers and comes out on top.

The reason that this is such a big deal right now is the fact that the 49ers have to get quarterback Colin Kaepernick signed to a big contract extension, and there are other members of the offensive line who could be going elsewhere. Iupati is entering a contract year and the 49ers don't have a replacement at left guard, unless they consider Jonathan Martin a potential candidate to fill in there.

At center, Goodwin could be going elsewhere. He's a free agent and the 49ers have not brought him back just yet. On the roster, there's not a whole lot of options at center beyond Daniel Kilgore, so it will be interesting to see where that goes. In other words, left guard and center could be seeing a change, while there's potential for some discontent at the left tackle position.

If the 49ers have shown anything in recent years, it's that they know their value for a player and will let anyone walk if the price doesn't match up with their beliefs. And on top of that, they've shown they know how to build a strong offensive line. It's unclear where this one is going, but nothing this current front office has shown should foster any doubt in fans' minds. Maybe they'll find money to extend Staley, Iupati and they'll draft a center. Maybe Martin has a place starting somewhere on the line in the future. Whatever the case may be, the 49ers have a proven track record of stocking these positions with Pro Bowl-caliber players.