But Sims persevered, as he has done throughout his career, and secured a reserve role before the season began. When duty called after Jonas Jennings went down for the final time as a 49er in Week 2, Sims got the call at right tackle and handled the job before being injured in late October. When his replacement, Adam Snyder, was hurt in December, Sims was ready to hop back into the starting lineup again, remaining there the rest of the season.
Sims was destined for a backup role again in 2008, when the 49ers brought in free agent Marvel Smith to become the presumptive starter at right tackle. Smith never made it out of training camp, and the starting role at right tackle went to Snyder.
But once again, Sims was ready when called upon, this time on the other side of the line. When Joe Staley was injured on the team's first offensive series of November, Sims took over without a dip in performance at the crucial left tackle position. Sims – who started 15 or more games at left tackle in six of his Oakland seasons – proved that he still has what it takes to hold firm at his natural position.
He did it once again last year, taking over at left tackle when Staley broke his leg in November, then starting San Francisco's final seven games while holding up notably well in pass protection.
That's 22 starts in three seasons for Sims, who some regarded as a retread veteran with not much left to give when he joined the 49ers. But Sims' reliability and flexibility during that span begs the question: Where would the 49ers have been without him after injury rocked their starting tackles each year?
The answer: Probably in worse shape than if Sims had not been around to step into their lineup in a pinch.
Now, after giving the 49ers three good years of service at a reasonable price, Sims is a free agent again at age 36, with 12 years of wear and tear in the NFL trenches behind him.
That factor alone suggests that the 49ers are interested in accelerating the development of youngster Alex Boone to possibly become their third tackle this season behind starters Anthony Davis and Staley, who is now fully recovered.
But like most young veterans without much game-day NFL experience, Boone's progress was stunted this year by not having an offseason program with San Francisco's new coaching staff to further his development. With the 49ers looking to keep Snyder at the interior line positions this year, Boone is the only player currently on San Francisco's roster that is a viable candidate this year for the No. 3 tackle role.
That makes Sims a more attractive commodity to the 49ers than he might have been four months ago, and also to other NFL teams that need veteran insurance at the all-important tackle positions.
The Sims breakdown
2010 performance: Started final seven games at left tackle after taking over for regular Joe Staley in November and played well, particularly in pass protection. Using a formula it applied to all NFL tackles that played at least 200 snaps on passing downs in 2010, Sims rated as by far San Francisco's best on the list in pass protection, making the top 15 at left tackle.
2010 season grade: B-minus
Why he's worth keeping: Sims has proven value as an experienced veteran who keeps himself ready to step into the fray at a moment's notice. He can play both tackle positions and provides quality veteran insurance at both corners of the offensive line. He has extensive starting experience at left tackle, the position that protects the blind side of San Francisco's quarterbacks.
Why he's not worth keeping: Sims turns 37 in December, and observers have been waiting for years to see an inevitable – and irreversible – decline in his skills. At this stage of his career Sims is not a strong run blocker, and bringing him back could just stand in the way of developing a younger player who may already be able to approach Sims' current level of performance.
Where he would fit with the 2011 49ers: If Sims returns, he will battle upstart Alex Boone for the No. 3 tackle role that Sims has held capably with the team over the past three seasons. He figures to compete for that role with any other tackle the 49ers might bring to training camp.
How he would be replaced: Boone would get first crack at the No. 3 role, and it would be his if he proves he can handle it. Since the two offensive linemen the 49ers selected in the April draft both are expected to move from tackle to the interior line positions, the 49ers likely would bring in another veteran to compete for playing time and provide insurance at the tackle positions.
Market interest level: Tepid. There doesn't figure to be a lot of initial interest in Sims on the open market, and he'll likely have to wait to be considered by other teams after the first few waves of free-agent tackles find their 2010 homes, meaning Sims still could be available after training camps begin.
49ers interest level: Attentive. As mentioned above, Sims is more attractive to the Niners now that they haven't had an offseason, like in ordinary years, to both identify and develop a younger replacement for the role Sims has held on their roster.
Sims is getting up there both in age and NFL punishment absorbed, but he is one of those aging veterans who has settled gracefully into a performance groove over the course of recent seasons. As long as he continues to play up to that standard, Sims has defined value to the 49ers, particularly since Boone is still an unknown commodity who is hurt by not having the benefit of an offseason program. If the 49ers don't re-sign Sims, they will likely have to find a comparable veteran in free agency to replace him and provide veteran insurance /competition at the tackle positions. Since Sims has been dependable and provided a solid veteran presence since joining the 49ers, he should stay, and the team should act quickly to offer him a short-term deal during the early window in free agency in which teams can sign their own impending free agents.