After 23 years as head football coach at the University of New Hampshire, Sean McDonnell had the feeling it was time for a change.

UNH announced his retirement early Wednesday morning and talked about his decision in an emotional news conference later in the day.

“It’s been weighing on me for over a year or so,” said McDonnell, a two-time national coach of the year in the NCAA’s Football Championship Subdivision.

McDonnell struggled to find words for a few moments before explaining why he decided to step down.

A 2020 season canceled by COVID-19 and a 2021 season that started with three straight wins but ended with eight straight losses helped clarify the matter.

“Losing the last eight games — that’s not it. It’s just a feeling I have,” he said.

Times have changed in college football and in the UNH program, he said. “There’s a lot of things you’re gonna have to put an enormous amount of energy into and effort into that I’m not used to.”

McDonnell, 66, missed the 2019 season while being treated for cancer.

“The challenges before I always attacked head-on,” he said. “I just feel like at this time there are better people to do that than Sean McDonnell.”

“Coach Mac” inspired great loyalty among his players, and he responded in kind.

He said he was most proud “that the kids represented the University of New Hampshire, the state of New Hampshire and this athletic department with class, and did it the right way.”

“We didn’t have everything everybody else had, but I believe we had more because of the way the kids were, the way they embraced it,” he said.

“We wanted to play with a chip on our shoulder. Wherever we went, I made sure they knew New Hampshire was there — that New Hampshire was going to leave a footprint wherever it was. And we did an awful lot of that.”

With McDonnell, UNH made 14 straight appearances in the FCS playoffs, reaching the national semifinals in 2013 and 2014.

“Words alone cannot capture what Sean McDonnell has meant to this university, the athletics department and the sport of football in the state of New Hampshire,” said UNH Athletic Director Marty Scarano, who himself is retiring at the end of the academic year.

An announcement on McDonnell’s replacement is expected soon. Associate Head Coach Ricky Santos, a UNH Hall of Fame quarterback who replaced McDonnell during his medical leave in 2019, is considered the leading candidate.

McDonnell played defensive back at UNH from 1975 to 1978 under his mentor, Bill Bowes. After graduation, he held several high school and college coaching jobs — including stints as an assistant at Manchester Memorial and West — before returning to UNH, where he coached under Bowes for five seasons before succeeding him as head coach in 1999.

His 157 career victories rank second in UNH history behind Bowes’ 175.

“I remember when it hit me that I wanted to coach here,” McDonnell said. “It was when (I was) coaching at Boston University and we were playing here, playing UNH and we’re driving back onto campus looking at things. I was coaching at a city school and thought that was a cool place, but when I walked back onto this campus, I knew it was the place I wanted to be.

“This place has done so much for me … so much for my family. Always felt like home — and it was. It was.”