Too often steamrolled by more physical teams, Grigson's roster now lacks impact talent on both sides of the ball.
To that end, Grigson was asked at the NFL Scouting Combine what he learned in a season of adversity that can be carried over to the 2016 season.
"Now I feel like we need to build that defense," Grigson said Thursday. "I feel like we have a lot of really good pieces on offense."
Echoing coach Chuck Pagano's emphasis on fixing the pass rush, Grigson cited the "old adage" that if a team has 12 pass rushers, they need 13.
It's not that Grigson hasn't poured resources into the offensive line and the defense. It's just that too many draft picks and free-agent acquisitions haven't panned out.
"You can take two different approaches. You can play it safe, scream through the rooftops, build through the draft," Grigson explained. "I feel like we were in a position to take swings at the plate."
Grigson noted that he would have taken heat from media and fans had he eschewed high-profile free agents at a time when Luck presented the organization with a playoff window.
Operating under the same premise this offseason, Grigson is going to keep swinging for the fences.
"I think that mindset of knowing you're going to make mistakes, but dusting yourself off and trying again, that's the culture of (Jim Irsay's Colts)," Grigson added. "That's why we expect to build this into a championship team still."