What's been biggest improvement in Colts offense?

After five years of being continually hounded, quarterback Andrew Luck hasn't been sacked in 125 consecutive snaps.

INDIANAPOLIS — Perhaps the most surprising revelation in how the Indianapolis Colts’ offensive line has been performing is that some of the players were unaware that quarterback Andrew Luck hasn’t been sacked in 125 consecutive snaps.

“Now you’re going to jinx us,” left tackle Anthony Castonzo said with a smile.

Luck’s “clean” streak is the longest of his seven-year career. And it’s especially noteworthy when considering the three-time Pro Bowl passer has taken his share of punishment since being selected No. 1 overall in 2012. He missed all of last season with a shoulder injury that required surgery, an injury he suffered and played with in 2015.

Luck was sacked 156 times in 70 starts entering this season. He’s taken just 10 sacks despite attempting a league-high 311 passes, including not being sacked once in the past two games, and all this behind an offensive line that has shuffled through 10 different starters and five combinations in seven games.

While there’s a lot to improve upon as the Colts (2-5) visit the Oakland Raiders (1-5) on Sunday, it’s fair to say the O-line has been the biggest offensive improvement so far.

“We’re doing some good things, but we can be better,” Luck said on Wednesday.

First-year head coach Frank Reich says protection starts with communication between center Ryan Kelly and the other linemen as well as with Luck.

“They have worked hard, good fundamentals and technique,” Reich said. “Good preparation, a big part of that is the quarterback, Andrew (Luck), has done a great job with the protection. He and Ryan Kelly are really the keys to it all. They need to be on the same page communicating. The backs play a huge role in it. They need to be completely clued in. The backs have done a phenomenal job.

“We have done a lot of chipping and helping the tackles when we can – you can’t do that all the time. So we really try to take – we have a protection plan every week that is a significant part of the game plan and just like every other part of the plan, a protection plan you want to slightly vary it every week in how you are going to help and make things look different but still do the same thing over and over.”

Reich was effusive in his praise of Kelly, a 2016 first-round selection who is playing the best football of his young career.

“Yeah, Ryan (Kelly) was excellent,” Reich said of his 25-year-old center’s play in a 37-5 home win over Buffalo last Sunday. “I think he’s been pretty good all year and really his leadership in that area and really in every area as far as the offensive line play has been good. But I think it keeps getting better every week.”

Despite losing several players to injury and not having Castonzo for the first five starts due to a hamstring injury, the Colts have endured. Even the recent loss of right guard Matt Slauson to a season-ending back injury two games ago didn’t leave the Colts hurting. Mark Glowinski, who didn’t play a down last year, has stepped in and been solid.

“There’s been guys that have been coming in and out a bunch, so it’s just having the communication,” Glowinski said.

He shook his head when asked about the Colts using 10 different offensive linemen and how they keep track of everything.

“You try not to think about it,” Glowinski said. “You’re just more worried about the opponent that you got.”

He chuckled when asked if his extensive facial hair represented a lucky beard.

“I’ve been growing this for a while,” Glowinski said. “I haven’t really touched it much since camp.”

The Colts’ O-line has continued to grow as well. For the first time in a long time, there’s no need to touch anything in the lineup.

“All I know is that, with the guys that we have, we’re just doing exactly what the other guys were doing,” he said. “We’ve just been working on our assignments, working as a group, communicating and striving to get better.”