INDIANAPOLIS – At first glance, the obvious trait is their age.
A half dozen free agent additions, all at least 29 years old, could find their way into the Colts starting lineup come September.
What Ryan Grigson saw in face-to-face meetings with these new Colts was a driving passion that he believes will infuse a young core on the verge of something special.
"When you sat down with those players, it just took you a few seconds to realize you were sitting amongst greatness and players that have one thing in mind, and that's to win a championship," Grigson said.
"I don't think you can hurt our efforts or our goals by adding guys that are all likeminded in that respect and that are wired to win."
These interactions between Grigson and player came after the Colts GM spent the early part of the 2015 offseason scrutinizing films of potential free agents.
He witnessed the production, still, at an age where many players begin to see a decline.
Looking deeper into the player, Grigson saw a veteran presence that is needed as the Colts replace two pillar locker room presences in Cory Redding and Reggie Wayne.
"We think that they add kind of an X-factor you hope in the postseason, through training camp and just as a whole as a mindset," Grigson said of this year's free agent class. "Those players are players that can be a working example of how you're supposed to perform as a pro at this level.
"We've evolved as a team and just our mindset, based on where we're at or where we feel we're at. We think those guys can help bridge a gap. We were one game away, but you don't want to also just get there to get there and then breath a sigh of relief, you want to get there and win it."
What Grigson is also getting in nearly his entire 2015 free agent haul is a trait that shows up in the film he watched this offseason.
The Colts GM rarely had to skip weeks of film to evaluate these players.
Despite their age, durability has been a staple of virtually every free agent the Colts signed in 2015.
-There's Trent Cole having missed just five career games in 10 NFL seasons.
-Frank Gore is one of only two running backs in the NFL that will enter 2015 having played in 64 straight games.
-Wide receiver Andre Johnson missed a Week 15 matchup last year versus the Colts (concussion), the lone contest he has sat out over the last three seasons.
-Kendall Langford is at the top of the durability mountain, having played in an NFL-best 112 straight games for a defensive lineman.
What Grigson is anticipating in 2015 is that these offseason moves will carry the Colts one peak higher on the mountain.
He has acquired players that have reached the point of their careers where there's little to question about their desire to be all in.
Come January, the Colts hope that these offseason traits lead to one more game played next season.
"Teams have (outmuscled us) repeatedly, and it's a hard pill to swallow," Grigson said explaining his offseason philosophy. "We need to go into these backyard brawls and be able to step up to that challenge -- and I need to be able to find players who will step up to that challenge.
"Trent, Gore, Johnson -- they know that mindset. They know that window's closing for them, and they're not gonna put up with much BS from young guys who don't quite get it. And they'll bring a vibe that permeates through every orifice of our organization: 'We're going to the mountaintop, and if you don't get on board, you're gonna get left behind.'"