Nick Harris had no reason to panic when he learned he'd be starting in one of the Browns' biggest games of 2021 just two days in advance.

Harris, a 2020 fifth-round draft pick, had spent most of his career until that point on the sidelines. He was a backup to center JC Tretter, who was placed on the COVID-19 list two days before the Browns' Christmas Day kickoff against the Packers at Lambeau Field. Playoff implications were on the line, and the Browns had to turn to Harris to fill the hole in the interior.

When Harris heard the news, he thought back to the practice reps he had taken in the 19 months since he was drafted. He felt comfortable and confident on the practice fields in Berea, and he didn't see any reason why he'd feel different in front of the thousands of raucous fans in Lambeau. 

"I've been here for two years and I was like, 'Well, it's time," Harris said in an interview on Cleveland Browns Daily. "I was just ready. I was like, 'Let's do it.' I just wanted to portray myself as a professional and just do my job."

The game ended in a 24-22 Browns loss, but the offense had no drop-off with Harris in the middle of the offensive line — he allowed zero sacks and snapped the ball smoothly, which is all the Browns could've asked.

Most importantly, Harris felt as though he belonged.

"I just felt comfortable," he said. "I was just like, 'Oh, I like this.'"

That feeling has stuck with Harris as he entered the offseason with the goal of becoming the Browns' starting center in 2022. He could be next in line after the Browns released Tretter in March, although he'll still have to compete for the job in training camp after Cleveland signed Ethan Pocic in free agency.

Harris' NFL sample size is small. He's only played more than two offensive snaps in three games in the league, but he played relatively well for a player that won't turn 24 until November and was regarded as a prospect who would need a few years to develop. His other two high-usage games were in 2020, when he needed to fill in as a right guard for the injured Wyatt Teller and Chris Hubbard in Weeks 15 and 16.

The waiting period for Harris, though, will be over if he can secure the job in August.

"I didn't take (waiting) as a negative at all," he said. "Obviously, there's times when you wish you were in there, but this is part of the process … All I gained was knowledge and practice reps with (the offensive line)."

Tretter, an eight-year veteran who had started all but one game for the Browns at center since 2017, was one of his biggest resources. He mastered the ability to stay healthy and consistent on the field, and Harris compiled a long list of tips and advice to follow in his footsteps whenever the time came.

Harris said Tretter told him to reach out to him if he ever needed more tips, even though he was no longer on the team.

"Just hearing him say that showed me he knew how he helped me, and we understood our relationship," Harris said. "He's a consummate pro, and it felt good for him to be like, 'If you ever need anything, reach out.'

"It was bittersweet because I did learn a lot from him."

Aside from a trip to Pompeii with his girlfriend, Harris hasn't taken many days off in the offseason. He's been completing daily workouts and training at CrossCountry Mortgage Campus and has been following nutrition plans from the team to ensure his body is in top shape for when training camp begins in July. He and other Browns players will be back on the practice fields for the start of offseason workouts on April 19.

A lot of work is left for Harris to meet his goal of being a starter in 2022, but he's never been one to feel pressure — as his lone start in 2021 suggested.

More starts could be on the way for Harris in the future, and he's ready to seize them.

"You learn, and when you get your opportunity, it's time to go," he said, "and I feel like this is a perfect opportunity to let loose now."