GREEN BAY — His top two centers had both been held out of practice this week and the only other natural reserve at the position recently dropped out due to injury.

Yet, Packers offensive coach James Campen stood at the podium in the Lambeau Field media auditorium Thursday calm and collected amid questions about the center spot going into Friday night’s preseason home opener against Cleveland.

Asked about his level of concern with Corey Linsley (hamstring) and JC Tretter (illness) possibly sitting out, Campen didn’t break stride in his response.

“We’ll be fine. No problems,” Campen said.

Don Barclay might have proved on Friday night why his position coach spoke with such ease. In his first in-game appearance at center, Barclay held his own in taking 73 snaps at the position in the Packers’ 17-11 win over the Browns.

Tretter was healthy enough to start but exited with the rest of the Packers’ starting offensive line following Green Bay’s first offensive series.

That left Barclay to handle the center duties for the remainder of the game despite only playing the position occasionally in practice over the past few seasons.

Barclay, who’s lined up everywhere this summer, received nearly all of the first-team snaps at center this week with Tretter ailing, and Linsley and Dartmouth rookie Jacob Flores injured.

However, there’s a big difference between a practice setting and an actual game. You’re responsible for making pre-snap calls and getting on the same page with your quarterback.

In Barclay’s case, he was working with two rookies, Joe Callahan and Marquise Williams. Along with plowing the way for the run game’s 151-yard day, Barclay helped create a serviceable pocket for both Callahan and Williams to operate in.

More importantly, there weren’t any poor snaps.

“I thought it went really good,” said Barclay, who’s entering his fifth NFL season. “Could touch a few things up here and there, but I thought it went well. Keep building, keep repping stuff and it will all work out.”

It’s a sign of progress for Barclay after what was an admittedly trying 2015, his first season back after the reconstructive knee surgery that sidelined him for all of 2014.

Known for his versatility and toughness, Barclay was a serviceable replacement at right tackle his first two years when Bryan Bulaga dealt with season-ending hip and knee injuries.

Thrown back into the fire last season due to injuries across the line, Barclay just didn’t look like himself. Working to re-establish confidence in the knee, Barclay endured his share of struggles in five starts.

“Coming off of that first year, taking my first rep in (training) camp … it was kind of hard at first getting adapted, trying everything,” Barclay said. “You have to trust and you have to go out there and battle. I definitely feel a big difference this year than that year.”

This offseason, Barclay went back to basics. He returned to his alma mater, West Virginia University, where he worked out with several former Mountaineers, including Seahawks guard Mark Glowinski and Bears receiver Kevin White.

No longer needing to rehab the knee, Barclay was able to concentrate solely on redeveloping his strength and mobility. Since re-signing in April, he’s looked more like the undrafted free agent who first cracked the Packers’ roster in 2012.

Barclay’s journey reminds Campen of former Packers tackle Mark Tauscher, who steadily improved the year after returning from his own torn anterior cruciate ligament.

“He’s crisper. He’s stronger. Playing with a better base,” Campen said recently of Barclay. “It didn’t surprise any of us that he would be better coming into camp off that ACL like most of them. … Certainly, Donnie plays every (position), too, like JC from that standpoint. He’s doing well.”

The competition on the offensive line has been tight this summer with the Packers adding two draft picks (Jason Spriggs and Kyle Murphy) to a room that’s already returning nine players with previous NFL experience.

Capable of playing all five spots on the offensive line, Barclay’s calling card remains his versatility. He passed his first test on Friday in showing he could handle center in a pinch.

Barclay understands one game doesn’t mean much in the grand scheme of things. There’s still three preseason games left and it’s consistency that ultimately wins jobs.

Friday’s performance wasn’t perfect – there was a first-quarter safety Barclay and the line would like to have back – but it otherwise marked progress.

Barclay isn’t afraid of the battle. Now a year stronger, it should only help him stay in the middle of the fray.

 “It was something you have to deal with,” said Barclay of the competition. “Never quit. Do whatever you can. Just keep scratching and clawing. I’m one of those guys who won’t quit. I’m always going to try to leave my mark.”