Star Colts offensive tackle Anthony Castonzo blocks everyone: defensive linemen, linebackers, and Nate Bryant, a 28-year-old system administrator who once called Indy’s offensive line pathetic.

“He got beat time after time,” Bryant says now when explaining the tweet he sent after a 2013 Dolphins–Colts matchup, adding he never thought the comment would get him blocked. “I felt like it was me being obvious when I tweeted.”

It’s cliché for athletes to say that they try to tune out critical comments. In this era of connectivity, it’s also virtually impossible — unless you’re Castonzo, who rearranged his life for the sole purpose of never hearing negative opinions about his play. Castonzo speculates that there’s now just one way for someone other than a coach to tell him how he or she feels about the Colts or their left tackle: mail a letter to Castonzo’s house.

Because Castonzo, 28, never saw that tweet from Bryant, or the 2014 tweet from now 35-year-old Colts fan Sean McDermott bemoaning a holding call against the Texans. Before he looks at his mentions, Castonzo has them prescreened by whoever is nearby — usually trainers, sometimes teammates — to guarantee that he never sees the critiques. This can be particularly hectic after games, but Castonzo carries out the practice round the clock, and the instructions are always the same: block anyone sharing an opinion.

“I say, ‘Hey, block anyone who says something bad,’” Castonzo said. “‘Block anyone who says something that I even remotely won’t like. Block anyone who is just too opinionated. Really, basically, anyone.’ I say, ‘This is my Twitter, I don’t need you on my feed.’”

Castonzo used to ask his girlfriend, Dominique, to handle the screening and blocking, but two years ago she started getting so furious at some of the mentions that he had to shift the responsibilities elsewhere. “She started to say, ‘I’m going to kill this person!’ and she’d get too pissed off,” Castonzo said. “So now I can’t hand the phone off to her, it has to go to someone else.”

Castonzo, as Dominique knows, is good at football. He’s not a scrub who’s afraid to face reality. He’s a former first-round pick who boasts the type of quickness needed to stop speed rushers, and the Colts gave him a four-year, $43 million extension last year because he was a bright spot on an otherwise average offensive line tasked with protecting prized quarterback Andrew Luck.

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That line has been heavily criticized, but Castonzo has no idea, and unless you mail that letter, you’ll almost certainly never be able to tell him that. This isn’t new: Between Castonzo’s junior and senior year at Boston College, he started to receive buzz as a high draft pick. He’d sit at his computer and read online breakdowns of his skills from amateur scouts who’d wonder if he was good enough to play left tackle at the elite level or good enough to play at all. The skeptics crept into his head, and that’s when he first hatched his tune-out strategy. “I was like, ‘Hey, you, random person on the internet saying these things, I don’t need this.’”

Castonzo’s rationale is straightforward: He already harshly criticizes himself, so he worries that hearing additional knocks will impact his confidence and thought process, and thus his play. Castonzo said he also worries slightly about what would happen to his game if he ever saw or heard too many positive opinions, but that’s much less of a risk in the troll-tastic digital age.

Around the time he began reading online assessments of his draft stock, Castonzo also read a book called Mind Gym: An Athlete’s Guide to Inner Excellence. From there, he started to embrace the power of positive thinking and prioritized talking to those in his life who he thought had a positive vibe. Based on those conversations, he devised a plan: stop reading about the draft, and then stop reading about football, period, in an effort to protect his on-field psyche.

Since then, he’s continued working to maintain a state of football silence. The plan was in full swing by the time he entered the NFL as the 22nd overall pick in 2011, and he swears he’s played his entire pro career without hearing a non-coach’s opinion about him or his teammates. “It’s my own football world that I’ve created and live in,” Castonzo said.

To keep that world intact, Castonzo avoids watching any sports coverage other than game broadcasts. If his TV is on, it likely means he’s watching Chopped or The Kitchen on Food Network or whatever’s on Cartoon Network, Comedy Central, or sometimes Netflix. He allows himself to watch prime time football broadcasts because, “I do not think the announcers are going to go ‘blah blah blah, Anthony Castonzo of the Colts really sucks.’” His only other football-film consumption comes from watching game tape to break down the opposing team during the offseason and in the week leading up to each contest.

The tackle also has to dodge large sections of interviews with reporters. The only reason he’s aware that people have been hammering the Colts’ line is because reporters have opened a question by saying “you must have heard the criticism…”

“And I stop them and say ‘Noooope, I haven’t heard anything, you’re telling me.’ Because I’ve done a good job at this,” Castonzo said. And so, after tuning out the premise of the question about the team’s struggles, Castonzo talks about how he blocks things out — but few know he’s speaking literally. Almost all of his answers turn the focus to his opinion of himself or his own observations about the team — no outside voices allowed. Last season, he told reporters he was “(expletive) terrible.”

“If I had to describe Anthony in one word, it would be ‘focus,’” said fellow offensive lineman Hugh Thornton. “He has his regimen and he doesn’t listen to anything on the outside. Absolutely no outside voices.”

There’s collateral damage, of course. The fans Castonzo automatically blocks are confused. McDermott and Bryant have sent tweets to get unblocked, but Castonzo hasn’t seen them, and Twitter mentions about the trend wouldn’t get through to him. McDermott said he thought Castonzo would “take it in stride.” “I guess not,” he said. “I have nothing against Castonzo.”

Castonzo understands that fans want to give feedback, but said he can’t take the risk of seeing something that would annoy him. He also said that he’s never heard in person from the legion of people he’s blocked. A fan could theoretically show up at training camp or a game and try to broach the topic, but that’s yet to happen to Castonzo, who said he’d focus on other things if it did.

“I’ve never had to deal with that because I do a great job at this plan,” Castonzo said.

Castonzo uses his purged version of Twitter to interact with friends and post nonfootball things. Photos of his dog, for instance, or critiques of Les Mis. He’ll share his thoughts on My Chemical Romance or Pokémon Go, but never on the team’s performance against the Jaguars.

He’s heard about, but never seen, one genre of tweet in which fans respond to players’ nonfootball tweets with a call to get back to studying the playbook. The very idea makes him angry: “Oh man, that’s definitely a block,” Castonzo said.

For most NFL offensive linemen, that means something else entirely.