But, as he so often states, he is going out a winner. The right-handed reliever earned two World Series rings (with the Angels in 2002 and Boston in '07), an All-Star Game victory, the "W" in the memorable Game 6 of the '02 Fall Classic and MLB.com's Setup Man of the Year Award in 2003. His lifetime record was 32-10 (.762 winning percentage), and he posted a 3.22 ERA with 369 strikeouts in 385 1/3 innings.
"I'm pretty grateful for the career I've had," Donnelly says. "I've done about everything in baseball that a player can do. I got to the big leagues, won World Series, made an All-Star team, and made a lot of friends along the way.
"Not to mention that everything after Day 1 of my big league career was something I never thought I would ever see."
Donnelly's decision to walk away from the game, or, as he says, with a laugh, "the game's decision to walk away from me," capped off a winter in which he was prepared to accept a Minor League deal and try to make a club, in what would have been his 20th Spring Training. He drew minimal interest from Major League teams this winter after being released by the Pittsburgh Pirates last July 29 with a 5.58 ERA and 26 walks in 30 2/3 innings.
But that isn't the only reason he's walking away. His wife, Rhonda, is six-months pregnant with their first child, and he's ready to begin pursuing opportunities in other facets of the game.
"Maybe it's time that I should be home more," he says, "and start the next chapter of my life."
Donnelly's tale of perseverance on the long, hard road to the Major Leagues is a colorful and eventful one.
He was selected by the Chicago White Sox in the 27th round of the 1992 First-Year Player Draft, after pitching at Mesa State in Grand Junction, Colo., but was released shortly before the 1993 Minor League season began. That set off a decade of nomadic job searches that saw him signed and released by the Cubs, Reds, Devil Rays, Pirates, Blue Jays and Cubs, again.
In 1999, while pitching well for Tampa Bay's Triple-A Durham club, he was asked to accept a demotion to make room for Jim Morris, about whom the Disney movie "The Rookie," with Dennis Quaid, would be made. Donnelly's own movie-worthy tale got a Hollywood payoff a few years later, when he settled in with the Angels organization in 2001, and finally made the big club in early 2002 at the age of 30.
He endured three trips back and forth between Anaheim and Triple-A Salt Lake that year, before sticking with the club in late July and solidifying the late-inning makeup of what turned out to be the best bullpen in the American League on the way to the postseason. He finished the regular season with a 2.17 ERA, struck out 54 batters in 49 2/3 innings, and became one of Scioscia's key late-game options setting up closer Troy Percival.
This continued that October, when Donnelly struggled in the first two rounds of the playoffs, before righting himself in the World Series. He appeared in five of the seven games and pitched a total of 7 2/3 scoreless innings -- earning the win in Game 6 when the Angels rallied from a 5-0 deficit to the Giants with seven outs left in their season. Donnelly also pitched shutout sixth and seventh innings in Game 7, as his team closed out San Francisco by a score of 4-1.
"He was an extremely important part of that team," says Bill Stoneman, the Angels' GM at the time, and now a consultant for the club. "And wow, what a competitor. He was about as competitive as you can get. Here was a guy who had gone through a lot, and nothing fazed him. And that carries over to other guys on the club."
His talent carried over to 2003, when Donnelly, wearing his trademark wraparound sport glasses, went on a rare tear to open the season.
He allowed two earned runs in his first 50 innings, to enter the All-Star break with the lowest midseason ERA (0.38) by a regular reliever in 14 years. The performance earned him a spot on the American League All-Star team, and he was the winning pitcher in the AL's 7-6 victory at Chicago. He finished the year with a 1.58 ERA and a career best three saves, taking home MLB.com's top honor for setup men.
"I've never seen anybody as unhittable as he was leading up to that All-Star Game," former Angels bench coach and current Tampa Bay manager Joe Maddon says. "I've never seen a guy miss so many bats. It was amazing how dominant he was.
"He had a unique personality, a unique delivery, and unique glasses. Just about everything about Brendan Donnelly was unique."
The remainder of Donnelly's career was marred by injuries -- including a severely broken nose in 2004 and elbow problems that eventually led to Tommy John surgery in 2007. But he earned a ring while with the 2007 Red Sox, and also played for Cleveland, Florida and Pittsburgh.
"The only way I was able to stay in the game, financially, was because my wife was able to earn the money that kept us going," Donnelly says. "She's really the reason I had a career -- sticking by me while living in practically every small town in America, hoping someone would notice me. In the end, baseball is what I love and what I know and what I do, and it's all I've ever known how to do well."
And what will he miss the most?
"Standing on the mound in a tight game where every pitch matters, and it's me against a great hitter -- knowing he's one of the best in the world," said Donnelly. "Just the opportunity to beat one of the best in the world. And the teammates. The clubhouse. I'm going to miss the camaraderie, being around the guys."
Donnelly says he'll forever be grateful to the Angels organization for giving him his first chance to put on a Major League uniform. He also says he has few regrets.
"You look at my stats, and it says I had seven years of service time spread out over nine years," Donnelly says.
"That's seven more than I ever thought I'd get."