"He was the heart and soul of that offense -- and really that team," Campbell explained. "... Playing against him, he is the guy. He's really the one we had to stop."
Now that Gore is 32 years old and playing outside the comfortable confines of San Francisco for the first time in his 11-year career, can the Colts expect their new backfield savior to keep stiff-arming Father Time?
The answer is a resounding yes, for several reasons.
Still the 'Inconvenient Truth'?
Will Gore's NFL swan song play out like Corey Dillon in New England (1,635 rushing yards, 12 touchdowns) and Stephen Davis in Carolina (1,444 rushing yards, 8 touchdowns) or more closely resemble the late-career flops of Steven Jackson in Atlanta (543 rushing yards, 6 touchdowns) and Emmitt Smith in Arizona (256 rushing yards, 2 touchdowns)?
If his 2014 season had ended in Week 15, we might assume the latter.
Gore was coming off the least effective stretch of his career, failing to top the 100-yard mark in nine consecutive games while averaging a scant 3.46 yards per carry over that span. The five-time Pro Bowler was being phased out of game plans with the offensive line severely backsliding from its 2012-2013 dominance.
What followed was one of the most impressive two-game stretches of Gore's career. He responded with 302 yards on 61 carries, marking the first time he had rushed for at least 140 yards in back-to-back games since November of 2006.
Although Gore may be the NFL's slowest starting running back at this stage of his career -- he finished near the bottom in Pro Football Focus' Elusive Rating and Breakaway Percentage metrics -- he remains effective via uncanny patience, vision and toughness.
Gore has actually averaged more rushing yards per season (1,165) since age 28 than he did in his first six years (1,069) in the league.
His 158-yard performance versus the Chargers in a 38-35 Week 16 loss was one of the most impressive all-around games by any tailback in 2014.
"Sustainability. He's a chain mover," NFL Films Senior Producer Greg Cosell recently explained. "I don't think there's been a back in the last five, six, seven years who has been able to get through small cracks at the point of attack better than Frank Gore. Frank Gore is your classic four-, five-, six-yard runner.
"He's probably past the point where he's going to break a 40-yarder. That wasn't really his game anyway. ... He would get so skinny going through the point of attack and come out the other end, I'd have to watch the play four or five times on film and try to figure out how did he get through there. And that's what he gives this offense. He gives them a sustaining element, so they'll be in more favorable down-and-distance situations."
Pep Hamilton's scheme
The big draw, Gore told NFL Media analyst LaDainian Tomlinson, was the presence of offensive coordinator Pep Hamilton, who learned under Jim Harbaugh at Stanford.
Ever since the ill-fated Richardson move in September of 2013, Hamilton has been crafting a power-running scheme featuring inside runs designed to soften the interior of opposing defenses.
It's the same scheme under which Gore thrived for the past half-decade in one of the NFL's most consistently successful power attacks.
Entering his twilight years, Gore wouldn't succeed in just any offense. Fortunately, Hamilton's is the one best suited to emphasize his unparalleled patience and vision.
"If you want to try and stop him and slow him down," Pagano said in early June, "I'd recommend you being in an eight-man spacing."
Going back to college, as NFL Media analyst Bucky Brooks explained in an informative 2013 feature, Luck pummeled opponents with a power running game that featured "check with me" calls based on defensive alignment.
If the presence of Gore leads to more loaded boxes, Luck will pick secondaries apart with high-percentage opportunities on the outside in early downs.
"One of the most improved players is going to be Gore," one NFL scout recently offered, via Bleacher Report's Mike Freeman. "He'll look like he's 22 years old in that offense. It's so wide-open, and Gore will have lots of room to run."
As is often the case, a poor pass-protection unit is perfectly adequate in paving lanes for the ground game.
Indianapolis running backs not named "Richardson" have averaged 4.7 yards on 350 carries over the past two years.
'Greatest 'Shoe on Earth'
This is nightmare fuel for opposing defensive coordinators.