INDIANAPOLIS — When sweeping changes are made, you either have to be prepared to go with the flow or risk falling out of favor. In a building full of new faces, one of the Indianapolis Colts' few elder statesmen knows that past accomplishments are no reason for complacency.

​"You kind of get that new sense of you've got to prove yourself," said Colts eighth-year left tackle Anthony Castonzo. "I think it's going to be good."

Over the last year and a half, the Colts have turned over a huge portion of their roster and have almost a completely new coaching staff in place as of this offseason. How well you played for the previous staff or front office doesn't hold much weight if you aren't showing new management what you're all about. Castonzo has been a mainstay at one of football's most important positions, but he knows he has to continue proving himself to new eyes.

"I think it's just that there's no real relationships. You've got to build relationships, and you build trust. It's not a relationship that you've shown people in the past, 'This is how I do things. This is how I play.' So, you've got to let all these people know anew that this is how I play, this is how I go about my business."

Being self-aware and using that trait to improve himself is nothing new to the Colts' blindside protector. Castonzo was noticeably more consistent as a player in 2017 after an up-and-down 2016 campaign. He attributed some of his missteps to overthinking things at times, telling the media he was "just being super hard on myself."

Castonzo said he was "letting one bad play turn into more or thinking something was a bad play because maybe a guy could've beaten me, even though he didn't, and me being like, 'Oh, I left this open for him,' and then overthinking it."

Castonzo was able to get the stressful thoughts out of his head in time to put forth a standout 2017 season; Pro Football Focus even graded him as one of the NFL's top 10 offensive tackles.

"I just kind of got out of that, and I'm like, 'I'm just going to go out there and just play some football,'" Castonzo said. "I stopped overthinking stuff, just kind of relaxed a little bit and it showed up."

So what is Castonzo looking to do this year to make sure his new coaches know what he is all about? Aside from keeping a clear mind, he is looking to become more physical, saying, "I've really been trying to get a lot stronger, faster, everything this offseason."

"I'm just trying to work on a lot of lower body drive and power, because, I mean, that's football," he said. "I want when a guy runs into me, I want him to feel it more than I feel it; get that force coming from the ground up, and just working on my lower body a lot."