INDIANAPOLIS, Ind. – The trip has been swift and dramatic.

From bum to brilliant, all in the span of two months.

We introduce you to Dave DeGuglielmo, who along with assistant Bobby Johnson is responsible for an Indianapolis Colts offensive line that suddenly – finally – is establishing itself as one of the NFL’s best.

“Ultimately you’re only as good as the players you have, and they’ve been playing pretty well,” DeGuglielmo said. “Still a lot of room for improvement.”

For too long, the offensive line served as a convenient and appropriate punch line as quarterbacks Andrew Luck and Jacoby Brissett were routinely roughed up while attempting to go about their business. Luck was sacked 156 times and hit more than 500 times during his first 70 regular-season games. Brissett was sacked a league-high 52 times while filling in for Luck last season, including 10 against Jacksonville.

Things remained spotty at the beginning of this season as injuries played havoc with continuity. Ten players have started at least one game, leading to five different starting combinations in the first six games.

Suddenly, all is good. The Colts haven’t allowed a sack in three consecutive games for the first time since 2009 and Luck’s protection hasn’t allowed a sack on his last 156 attempts. That’s the longest sackless streak since Peyton Manning delivered 186 straight passes during a stretch that spanned 2009-10.

Anthony Castonzo has returned to left tackle after missing five games with a hamstring injury. Mark Glowinski stepped in at right guard after Matt Slauson suffered a season-ending neck injury in week 5 at New England while rookie Braden Smith has settled in at right tackle. Rookie left guard Quenton Nelson and center Ryan Kelly have been the eight-game constants.

Consider the pedigree of the combo that has been intact the last three games: Castonzo (2011), Nelson (2018) and Kelly (2016) are first-round picks; Smith is a second-rounder (2018) and Glowinksi a fourth-rounder (by Seattle in ’15).

“I’m very fortunate to have the players that I have,” DeGuglielmo said. “Some years I’m a good coach, some years I’m a bad coach. A lot of that is based on who’s out there playing. I don’t think my coaching style’s ever changed.

“When you’ve got three first-rounders, a second-rounder and a fourth-rounder all playing pretty high-level football right now, I guess I’m a good coach now. I was a bum a month ago. Now, I’m a pretty good coach.”

The early-season adjustments due to injuries are part of “the modern-day NFL,” he said. “It’s just unfortunate, but these are big men beating each other up pretty good out there. It’s a tough job.

“If it were easy, everyone would do it, and there’s a lot of big people walking around that can’t. These guys do a very tough thing for a profession.”

DeGuglielmo looks the part of offensive line coach. He’s short, thick, bald. A mustache and goatee, each tinged with white, mold his face. He’s quick to turn a phrase, and his affinity for the guys in his meeting room is obvious.

“They’re blue-collar work guys,” he said. “These are the guys that dig holes. They work with jackhammers every day. There’s no glory for these guys. If it weren’t for them, nothing else happens.”

Here’s a capsule look at the Colts’ starting O-line, from DeGuglielmo’s vantage point:

C Ryan Kelly: “I’ve coached Pro Bowl centers. I’ve been around Nick Mangold, (Mike) Pouncey. I’ve had some really good, athletic ones, strong ones, smart ones. He’s he most complete center I’ve ever coached. I have no doubt he is the best center in the National Football League. He’s the most complete guy. Turn the tape on, find me one better. Strength, athletic ability, intelligence, quickness.

“You have to struggle to find a flaw at that position with that guy. He’s everything they thought he’d be when they drafted him. Guys like me that were in different places at the time were like, ‘Those lucky sons of guns, they got him.’ The difference between his play now and last year, he’s letting that natural aggression (out). His physical play is really coming out. He’s actually physically moving people and getting after people at the second level and the edges.”

LT Anthony Castonzo: “When I first got here they asked me about some free agents. I told them I was not interested in a free-agent left tackle because I felt we had a left tackle here that was of the elite level. Has he had up-and-down moments? Of course. Tell me one that hasn’t, including the one that got paid a lot of money last year to go to New York (Nate Solder). We didn’t have to go out there and get one because we had one.

“Anthony no longer is the elite guy among a bunch of guys. He’s among a bunch of elite guys now. That’s a lot of relief off of him. He doesn’t have to be the guy. He doesn’t have to carry the line. He’s just one piece of a line that’s some pretty talented cats. He’s playing next to a really special guy and like I said, that center is as good as it gets. He’s got two right next to him . . . he’s got to play up to their level some times.”

LG Quenton Nelson: “He’s a good football player, a really good football player. In this league you’re going to play against some great defensive players. Every so often he runs into a move he hadn’t seen before. The great thing about Quenton is he studies that piece of film or analyzes what he did on the play and he works on it so it doesn’t happen again. If he keeps doing that, he’s just going to get better and better.

“A lot of times you pick a player in the first round and he’s a good player. This guy’s an exceptional football player who’s come in right away and (made an) impact. I think putting Anthony next to him, next to Ryan, I’ve got a pretty formidable left side.

“Quenton’s an exceptional puller. Most amazing thing he can do, although it doesn’t look like he’s moving very fast, he gets to Point A to Point B as quick and as efficiently as any guy I’ve coached. But the amazing thing is he can make adjustments inside and out. It’s really unique he can do that with his girth.”

RT Braden Smith (almost exclusively a guard at Auburn): “We had him (at tackle) in the summer a little bit for a reason. He’s a tremendous athlete. He’s big. I don’t really go by the labels. People say he’s mainly a guard or what is the common term that everybody’s been using? A natural guard? I’m not buying that.

“He’s an offensive lineman. He’s a football player. How many times do they draft a tackle to play guard? They do it all the time. This guy’s 6-foot-6-and-a-half. The bottom line is he’s a good athlete and a good football player. He’s smart, he’s tough, he’s strong. Probably one of the strongest guys on the team. If he had played for Michigan State he would have been a tackle and he probably would have been a first-round tackle.

“Has he had some struggles? Everybody has struggles when they play as a rookie no matter who you are, including Quenton. Those two young men are as good as you can get.”

RG Mark Glowinski: “I’ve seen where several people are labeling him a ‘journeyman.’ But if he’s a journeyman, so is Jack Doyle because he’s been with two teams. It’s not like he’s been (a lot of places). He started (19) games in the league. Kelly started 23 games before this season.

“Mark brings a little bit of a uniqueness in his play because he’s very, very aggressive. I mean he probably had five cuts, five knockdowns and three what I would call bonus blocks this past week alone. He was off the charts.”

You can follow Mike Chappell on Twitter at @mchappell51